National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/3460

TDMS Study 05040-01 Pathology Tables

NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97
Route: GAVAGE                                                                                                     Time: 08:40:29




       Facility:  American Biogenics Corp.

       Chemical CAS #:  000123319

       Lock Date:  None

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All




































Note:  Animals arranged according to CID number

                                                              Page   1

NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 5| 7| 7| 7| 7| 4| 7| 7| 7| 5| 3| 7| 7| 7| 6| 6| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 3| 2| 2| 0| 0| 3| 3| 3| 0| 5| 3| 3| 2| 7| 7| 3| 3| 3| 5| 4| 3| 3| 3| 2| 5|             
                                           | 1| 9| 2| 1| 0| 1| 0| 0| 2| 8| 1| 1| 9| 5| 2| 0| 0| 0| 8| 6| 1| 0| 0| 9| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                        X                                 |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                             X  X                                 |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +                                                                  |             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                        +                                 |             
      Pulp, Leukemia Mononuclear           |                                        X                                 |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                X                                 |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                X                                 |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                                                  |             
      Pheochromocytoma Malignant           |                X                                                         |             
      Pheochromocytoma Benign              |       X                                                                  |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  M  +  +  +  +     +  +  +  +  +  +  +  M  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   2                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 5| 7| 7| 7| 7| 4| 7| 7| 7| 5| 3| 7| 7| 7| 6| 6| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 3| 2| 2| 0| 0| 3| 3| 3| 0| 5| 3| 3| 2| 7| 7| 3| 3| 3| 5| 4| 3| 3| 3| 2| 5|             
                                           | 1| 9| 2| 1| 0| 1| 0| 0| 2| 8| 1| 1| 9| 5| 2| 0| 0| 0| 8| 6| 1| 0| 0| 9| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |       X                                X                                 |             
      Pars Distalis, Adenoma               |             X     X     X                                X        X      |             
      Pars Distalis, Carcinoma             |                                                                X         |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
      Bilateral, C-Cell, Adenoma           |                                                                          |             
      C-Cell, Adenoma                      |                                  X  X                                    |             
      C-Cell, Carcinoma                    |    X                                                           X         |             
      Follicular Cell, Adenocarcinoma      |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +     +  M  +  M  M  +  +  +  +  +  +  +  +  +   |             
      Adenoma                              |    X                                X           X                        |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Granulosa Cell Tumor Malignant       |                                                                          |             
      Leukemia Mononuclear                 |                                        X                                 |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
      Polyp Stromal                        |    X                                                  X        X         |             
      Endometrium, Sarcoma Stromal         |          X                                                               |             
                                            __________________________________________________________________________|             
   Vagina                                  | +                                                     +                  |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |       +                                +                                 |             
      Leukemia Mononuclear                 |       X                                X                                 |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                X                                 |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Inguinal, Leukemia Mononuclear       |                                                                          |             
      Mediastinal, Leukemia Mononuclear    |       X                                                                  |             
      Pancreatic, Leukemia Mononuclear     |       X                                X                                 |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                X                                 |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                X                                 |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                             X  X                                 |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  M     +  +  +  +  M  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                X                                 |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   3                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 5| 7| 7| 7| 7| 4| 7| 7| 7| 5| 3| 7| 7| 7| 6| 6| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 3| 2| 2| 0| 0| 3| 3| 3| 0| 5| 3| 3| 2| 7| 7| 3| 3| 3| 5| 4| 3| 3| 3| 2| 5|             
                                           | 1| 9| 2| 1| 0| 1| 0| 0| 2| 8| 1| 1| 9| 5| 2| 0| 0| 0| 8| 6| 1| 0| 0| 9| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Adenocarcinoma                       |                                                          X               |             
      Adenocarcinoma, Multiple             |                                                                          |             
      Fibroadenoma                         |    X     X  X     X  X  X     X  X     X           X     X     X         |             
      Fibroadenoma, Multiple               |                                                                   X      |             
      Leukemia Mononuclear                 |                                        X                                 |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |       X                                X                                 |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +     +   |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                        +                                 |             
      Leukemia Mononuclear                 |                                        X                                 |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                                                  |             
      Meninges, Leukemia Mononuclear       |       X                                                                  |             
      Pons, Carcinoma, Metastatic          |                                                                X         |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |       +  +  +                             +                              |             
      Leukemia Mononuclear                 |                                                                          |             
      Meninges, Leukemia Mononuclear       |       X                                                                  |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                X                                 |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                X                                 |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     | +                                                                        |             
                                            __________________________________________________________________________|             
   Harderian Gland                         | +                                                                        |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                X                                 |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                X                                 |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                             X  X                                 |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   4                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 4| 7| 7| 7| 6| 4|             
                             DAY ON TEST   | 2| 2| 2| 5| 5| 3| 3| 2| 5| 5| 3| 3| 3| 5| 5| 3| 2| 2| 4| 5| 3| 3| 2| 7| 5|             
                                           | 9| 9| 9| 3| 8| 1| 0| 9| 8| 8| 1| 1| 1| 8| 8| 1| 9| 9| 7| 8| 1| 1| 9| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                X                                                         |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                                   X  X                  |             
                                            __________________________________________________________________________|             
   Mesentery                               |                +                    +                 +                  |             
      Leukemia Mononuclear                 |                X                                      X                  |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Tooth                                   |                +                                      +                  |             
      Pulp, Leukemia Mononuclear           |                X                                      X                  |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X                                            X                  |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                                      X                  |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                                   X  X                  |             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   5                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 4| 7| 7| 7| 6| 4|             
                             DAY ON TEST   | 2| 2| 2| 5| 5| 3| 3| 2| 5| 5| 3| 3| 3| 5| 5| 3| 2| 2| 4| 5| 3| 3| 2| 7| 5|             
                                           | 9| 9| 9| 3| 8| 1| 0| 9| 8| 8| 1| 1| 1| 8| 8| 1| 9| 9| 7| 8| 1| 1| 9| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                X                                      X                  |             
      Pars Distalis, Adenoma               | X  X  X           X  X        X  X  X                       X     X  X   |             
      Pars Distalis, Carcinoma             |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
      Bilateral, C-Cell, Adenoma           |                                                                          |             
      C-Cell, Adenoma                      |       X           X                                                  X   |             
      C-Cell, Carcinoma                    |                                                       X                  |             
      Follicular Cell, Adenocarcinoma      |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Adenoma                              |                                                                          |             
      Leukemia Mononuclear                 |                                                    X                     |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Granulosa Cell Tumor Malignant       |                      X                                                   |             
      Leukemia Mononuclear                 |                X                                                         |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                X                                   X  X                  |             
      Polyp Stromal                        | X                             X                 X     X                  |             
      Endometrium, Sarcoma Stromal         |                                                                          |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |          +     +                                   +  +                  |             
      Leukemia Mononuclear                 |          X     X                                   X  X                  |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X                                            X                  |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Inguinal, Leukemia Mononuclear       |          X                                                               |             
      Mediastinal, Leukemia Mononuclear    |                X                                                         |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X                                            X                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +        +  +  +        M  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                                      X                  |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                                   X  X                  |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +     +  +  +        +  +  +        +  +  M  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                                      X                  |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   6                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 4| 7| 7| 7| 6| 4|             
                             DAY ON TEST   | 2| 2| 2| 5| 5| 3| 3| 2| 5| 5| 3| 3| 3| 5| 5| 3| 2| 2| 4| 5| 3| 3| 2| 7| 5|             
                                           | 9| 9| 9| 3| 8| 1| 0| 9| 8| 8| 1| 1| 1| 8| 8| 1| 9| 9| 7| 8| 1| 1| 9| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Adenocarcinoma                       |                                                                          |             
      Adenocarcinoma, Multiple             | X                                                                        |             
      Fibroadenoma                         | X     X        X                 X  X                       X  X  X  X   |             
      Fibroadenoma, Multiple               |                                                                          |             
      Leukemia Mononuclear                 |                                                    X                     |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |                                                       X                  |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X                                                               |             
      Meninges, Leukemia Mononuclear       |                X                                      X                  |             
      Pons, Carcinoma, Metastatic          |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |          +                                            +                  |             
      Leukemia Mononuclear                 |                                                       X                  |             
      Meninges, Leukemia Mononuclear       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                                      X                  |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                                      X                  |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                              +                           |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                              +                           |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                                   X  X                  |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |                X                                      X                  |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                                   X  X                  |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   7                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 1| 8| 3| 3| 3| 3| 2| 3| 2| 8| 7| 5|                             |            |
                                           | 1| 0| 9| 0| 6| 1| 0| 0| 0| 9| 1| 9| 5| 6| 8|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|                             |     A      |
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|                             |     L      |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  A  +  +  A  +                                 |  53        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  A  +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |       X  X                                                               |          9 |
                                            __________________________________________________________________________|____________|
   Mesentery                               | +                          +           +                                 |   7        |
      Leukemia Mononuclear                 |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Stomach                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                                          |   3        |
      Pulp, Leukemia Mononuclear           |                                                                          |          3 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |          X                                                               |          5 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |          X                                                               |          6 |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |          X                                                               |          6 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page   8                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 1| 8| 3| 3| 3| 3| 2| 3| 2| 8| 7| 5|                             |            |
                                           | 1| 0| 9| 0| 6| 1| 0| 0| 0| 9| 1| 9| 5| 6| 8|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|                             |     A      |
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|                             |     L      |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Pheochromocytoma Malignant           |                                                                          |          1 |
      Pheochromocytoma Benign              |                   X                                                      |          2 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  53        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  M  +  +  +  +  +  +  +                                 |  54        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  A  +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |                                                                          |          4 |
      Pars Distalis, Adenoma               |    X     X     X  X  X           X     X                                 |         23 |
      Pars Distalis, Carcinoma             |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Bilateral, C-Cell, Adenoma           |                                  X                                       |          1 |
      C-Cell, Adenoma                      | X        X           X                                                   |          8 |
      C-Cell, Carcinoma                    |                   X                                                      |          4 |
      Follicular Cell, Adenocarcinoma      |                                     X                                    |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  M  +  +  +  +                                 |  51        |
      Adenoma                              |          X                                                               |          4 |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Granulosa Cell Tumor Malignant       |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          3 |
      Polyp Stromal                        | X     X        X  X                 X                                    |         12 |
      Endometrium, Sarcoma Stromal         |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                                          |   2        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |          +                 +                                             |   8        |
      Leukemia Mononuclear                 |          X                                                               |          7 |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |          X                                                               |          5 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Inguinal, Leukemia Mononuclear       |       X                                                                  |          2 |
      Mediastinal, Leukemia Mononuclear    |          X                                                               |          3 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page   9                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 1| 8| 3| 3| 3| 3| 2| 3| 2| 8| 7| 5|                             |            |
                                           | 1| 0| 9| 0| 6| 1| 0| 0| 0| 9| 1| 9| 5| 6| 8|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|                             |     A      |
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|                             |     L      |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Pancreatic, Leukemia Mononuclear     |          X                                                               |          3 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |       X                                                                  |          5 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +                                 |  53        |
      Leukemia Mononuclear                 |       X  X                                                               |          7 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |       X  X                                                               |          9 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  52        |
      Leukemia Mononuclear                 |          X                                                               |          6 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Adenocarcinoma                       |          X                                                               |          2 |
      Adenocarcinoma, Multiple             |                                                                          |          1 |
      Fibroadenoma                         | X  X        X     X  X        X  X                                       |         28 |
      Fibroadenoma, Multiple               |                                                                          |          1 |
      Leukemia Mononuclear                 |          X                                                               |          3 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Subcutaneous Tissue, Leukemia        |                                                                          |            |
          Mononuclear                      |                                                                          |          3 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  54        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          2 |
      Meninges, Leukemia Mononuclear       |                                                                          |          3 |
      Pons, Carcinoma, Metastatic          |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |          +                             +                                 |   8        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Meninges, Leukemia Mononuclear       |          X                                                               |          2 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |          X                                                               |          6 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  10                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 1| 8| 3| 3| 3| 3| 2| 3| 2| 8| 7| 5|                             |            |
                                           | 1| 0| 9| 0| 6| 1| 0| 0| 0| 9| 1| 9| 5| 6| 8|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|                             |     A      |
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|                             |     L      |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |                                                                          |          5 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   2        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   2        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          6 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          4 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |       X  X                                                               |          9 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  11                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 7| 7| 7| 5| 4| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 6| 6| 6|             
                             DAY ON TEST   | 2| 7| 5| 5| 7| 3| 3| 3| 9| 8| 3| 2| 5| 5| 5| 3| 3| 3| 3| 7| 3| 2| 6| 5| 2|             
                                           | 1| 2| 8| 8| 3| 1| 0| 0| 5| 7| 1| 4| 8| 8| 8| 1| 1| 1| 0| 6| 0| 9| 7| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +        +           A  +     +                       A        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +        +           A  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +        +           +  +     +                       +        +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +        +           A  +     +                       A        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +        +           A  +     +                       A        +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                          X  X        X   |             
                                            __________________________________________________________________________|             
   Mesentery                               |                            +                    +        +           +   |             
      Leukemia Mononuclear                 |                                                          X           X   |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Pharynx                                 |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +        M           +  +     +                       +        +  +  +|             
      Leukemia Mononuclear                 |                                                          X               |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +        +           +  +     +                       +        +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +        +           +  +     +                       +        +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                       +                  |             
      Squamous Cell Papilloma              |                                                       X                  |             
                                            __________________________________________________________________________|             
   Tooth                                   |             +                                            +               |             
      Pulp, Leukemia Mononuclear           |                                                          X               |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +        +           +  +     +                       +        +  +  +|             
      Leukemia Mononuclear                 |                                                          X           X   |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                          X  X        X   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                          X           X   |             
      Pheochromocytoma Malignant           |                               X                                          |             
      Pheochromocytoma Complex             |                                                                          |             
      Bilateral, Pheochromocytoma Benign   |                                                                         X|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +        +           M  +     +                       M        +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  12                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 7| 7| 7| 5| 4| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 6| 6| 6|             
                             DAY ON TEST   | 2| 7| 5| 5| 7| 3| 3| 3| 9| 8| 3| 2| 5| 5| 5| 3| 3| 3| 3| 7| 3| 2| 6| 5| 2|             
                                           | 1| 2| 8| 8| 3| 1| 0| 0| 5| 7| 1| 4| 8| 8| 8| 1| 1| 1| 0| 6| 0| 9| 7| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
      Pars Distalis, Adenoma               | X              X              X  X           X              X  X  X  X   |             
      Pars Distalis, Carcinoma             |                                                                          |             
      Pars Distalis, Leukemia Mononuclear  |                                                          X               |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                      X                                                   |             
      C-Cell, Carcinoma                    |                                                                          |             
      Follicular Cell, Adenocarcinoma      |                                                                          |             
      Follicular Cell, Adenoma             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | M  +        +           +  M  M  +                       +        +  +  +|             
      Adenoma                              |    X                             X                                       |             
      Leukemia Mononuclear                 |                                                          X               |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +        +           +  +     +                       +        +  +  +|             
      Granulosa Cell Tumor Malignant       |                                                                          |             
      Leukemia Mononuclear                 |                                                          X               |             
      Luteoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Leiomyosarcoma                       |                                                                          |             
      Leukemia Mononuclear                 |                                                                      X   |             
      Polyp Stromal                        |                                                                      X  X|             
      Bilateral, Polyp Stromal             |                                                                          |             
      Endometrium, Adenocarcinoma          |                      X                                                   |             
      Endometrium, Sarcoma Stromal         |                            X                                             |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                         +|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                                                                      +   |             
      Leukemia Mononuclear                 |                                                                      X   |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +        +           +  +     +                       +        +  +  +|             
      Leukemia Mononuclear                 |                                                          X           X   |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +        +           +  +     +                       +        +  +  +|             
      Mediastinal, Leukemia Mononuclear    |                                                                          |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +        M           +  +     +                       +        +  +  +|             
      Leukemia Mononuclear                 |                                                          X               |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +        +           +  +     +                       +        +  +  +|             
      Leukemia Mononuclear                 |                                                          X           X   |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                          X  X        X   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  13                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 7| 7| 7| 5| 4| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 6| 6| 6|             
                             DAY ON TEST   | 2| 7| 5| 5| 7| 3| 3| 3| 9| 8| 3| 2| 5| 5| 5| 3| 3| 3| 3| 7| 3| 2| 6| 5| 2|             
                                           | 1| 2| 8| 8| 3| 1| 0| 0| 5| 7| 1| 4| 8| 8| 8| 1| 1| 1| 0| 6| 0| 9| 7| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +        +           +  +     +           M           +        +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                              X                           |             
      Fibroadenoma                         | X  X              X     X     X              X        X     X           X|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +        +           +  +     +                       +        +  +  +|             
      Basal Cell Adenoma                   |             X                                                            |             
      Keratoacanthoma                      |                                                                          |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |                                                          X           X   |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +        +           +  +     +                       +        +  +  +|             
      Cartilage, Adenocarcinoma, Extension,|                                                                          |             
           Metastatic, Thyroid Gland       |                                                                          |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +        +           +  +     +                       +        +  +  +|             
      Astrocytoma Malignant                |                                                                          |             
      Leukemia Mononuclear                 |                                                          X           X   |             
      Meninges, Leukemia Mononuclear       |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |             +              +                                         +   |             
      Leukemia Mononuclear                 |                                                                          |             
      Meninges, Leukemia Mononuclear       |                                                                      X   |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +        +           +  +     +                       +        +  +  +|             
      Alveolar/Bronchiolar Carcinoma       |                                                                          |             
      Leukemia Mononuclear                 |                                                          X           X   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +        +           +  +     +                       +        +  +  +|             
      Leukemia Mononuclear                 |                                                          X           X   |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +        +           +  +     +                       +        +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                M                                                         |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  14                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 7| 7| 7| 5| 4| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 6| 6| 6|             
                             DAY ON TEST   | 2| 7| 5| 5| 7| 3| 3| 3| 9| 8| 3| 2| 5| 5| 5| 3| 3| 3| 3| 7| 3| 2| 6| 5| 2|             
                                           | 1| 2| 8| 8| 3| 1| 0| 0| 5| 7| 1| 4| 8| 8| 8| 1| 1| 1| 0| 6| 0| 9| 7| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                                                          X           X   |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +        +           +  +     +                       +        +  +  M|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                          X  X        X   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  15                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 5| 7| 7| 7| 7| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 7| 4| 6|             
                             DAY ON TEST   | 3| 3| 2| 2| 6| 3| 3| 1| 0| 5| 3| 3| 2| 1| 4| 2| 2| 0| 5| 3| 2| 0| 0| 5| 5|             
                                           | 1| 1| 5| 4| 0| 1| 1| 9| 0| 8| 1| 0| 9| 0| 4| 9| 9| 8| 5| 3| 9| 0| 0| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    25 MG/KG                               | 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Large                         |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  |       +  A  +        A  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  |       +  +  +        +  +              A  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Intestine Small                         |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  |       +  A  +        +  +              A  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                |       +  A  +        A  +              A  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Leukemia Mononuclear                 |    X  X  X        X                 X              X  X     X     X      |             
                                            __________________________________________________________________________|             
   Mesentery                               |          +           +                    +                    +  +     +|             
      Leukemia Mononuclear                 |          X                                                        X      |             
                                            __________________________________________________________________________|             
   Pancreas                                |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Pharynx                                 |                      M                                            +      |             
                                            __________________________________________________________________________|             
   Salivary Glands                         |       +  +  +        M  +              +  +        +  +  +     +  +     +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach                                 |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
      Squamous Cell Papilloma              |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |          +                                                               |             
      Pulp, Leukemia Mononuclear           |          X                                                               |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Leukemia Mononuclear                 |       X  X                                         X              X      |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Leukemia Mononuclear                 |       X  X                                         X        X            |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Leukemia Mononuclear                 |       X  X                                         X        X            |             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Complex             |                                                                          |             
      Bilateral, Pheochromocytoma Benign   |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       |       +  +  +        M  +     M        +  +        M  +  +  M  +  +     +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  M  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  16                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 5| 7| 7| 7| 7| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 7| 4| 6|             
                             DAY ON TEST   | 3| 3| 2| 2| 6| 3| 3| 1| 0| 5| 3| 3| 2| 1| 4| 2| 2| 0| 5| 3| 2| 0| 0| 5| 5|             
                                           | 1| 1| 5| 4| 0| 1| 1| 9| 0| 8| 1| 0| 9| 0| 4| 9| 9| 8| 5| 3| 9| 0| 0| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    25 MG/KG                               | 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
      Pars Distalis, Adenoma               |                                  X     X        X     X  X              X|             
      Pars Distalis, Carcinoma             |                      X                                                   |             
      Pars Distalis, Leukemia Mononuclear  |          X                                                               |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  M  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      C-Cell, Adenoma                      |                                              X                 X         |             
      C-Cell, Carcinoma                    |                                                                          |             
      Follicular Cell, Adenocarcinoma      |                                                                          |             
      Follicular Cell, Adenoma             |                               X                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          |       +  +  +  M     M  +     M        +  M        M  +  +     +  +     +|             
      Adenoma                              |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Granulosa Cell Tumor Malignant       |                                                                          |             
      Leukemia Mononuclear                 |       X  X                                                               |             
      Luteoma                              |          X                                                               |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Leiomyosarcoma                       |                                           X                              |             
      Leukemia Mononuclear                 |          X                                                               |             
      Polyp Stromal                        |                   X     X     X                                          |             
      Bilateral, Polyp Stromal             |                                                          X               |             
      Endometrium, Adenocarcinoma          |                                                                          |             
      Endometrium, Sarcoma Stromal         |                                                                          |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |       +  +  +                                      +  +           +      |             
      Leukemia Mononuclear                 |       X  X                                         X  X           X      |             
                                            __________________________________________________________________________|             
   Bone Marrow                             |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Leukemia Mononuclear                 |       X  X                                         X                     |             
                                            __________________________________________________________________________|             
   Lymph Node                              |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Mediastinal, Leukemia Mononuclear    |          X                                         X                     |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Leukemia Mononuclear                 |       X  X                                         X                     |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Leukemia Mononuclear                 |       X  X                                         X              X      |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Leukemia Mononuclear                 |    X  X  X        X                 X              X  X     X     X      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  17                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 5| 7| 7| 7| 7| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 7| 4| 6|             
                             DAY ON TEST   | 3| 3| 2| 2| 6| 3| 3| 1| 0| 5| 3| 3| 2| 1| 4| 2| 2| 0| 5| 3| 2| 0| 0| 5| 5|             
                                           | 1| 1| 5| 4| 0| 1| 1| 9| 0| 8| 1| 0| 9| 0| 4| 9| 9| 8| 5| 3| 9| 0| 0| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    25 MG/KG                               | 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  |       +  +  +        +  +        M  M  +  M        +  +  +     +  +     +|             
      Leukemia Mononuclear                 |       X  X                                         X              X      |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Adenoma                              |                                     X                                    |             
      Fibroadenoma                         |                X     X  X     X        X           X        X  X        X|             
                                            __________________________________________________________________________|             
   Skin                                    |    +  +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Basal Cell Adenoma                   |                                                                          |             
      Keratoacanthoma                      |                                                                          |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |          X                                                               |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Cartilage, Adenocarcinoma, Extension,|                                                                          |             
           Metastatic, Thyroid Gland       |                                                                          |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |          +                                                               |             
      Leukemia Mononuclear                 |          X                                                               |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Astrocytoma Malignant                |                                        X                                 |             
      Leukemia Mononuclear                 |          X                                                               |             
      Meninges, Leukemia Mononuclear       |          X                                                               |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |          +  +                             +                              |             
      Leukemia Mononuclear                 |          X                                                               |             
      Meninges, Leukemia Mononuclear       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    |       +  +  +  +     +  +              +  +        +  +  +     +  +     +|             
      Alveolar/Bronchiolar Carcinoma       |                X                                                         |             
      Leukemia Mononuclear                 |       X  X                                         X                     |             
                                            __________________________________________________________________________|             
   Nose                                    |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Trachea                                 |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |             +                                                            |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |             +                                                            |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  18                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 5| 7| 7| 7| 7| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 7| 4| 6|             
                             DAY ON TEST   | 3| 3| 2| 2| 6| 3| 3| 1| 0| 5| 3| 3| 2| 1| 4| 2| 2| 0| 5| 3| 2| 0| 0| 5| 5|             
                                           | 1| 1| 5| 4| 0| 1| 1| 9| 0| 8| 1| 0| 9| 0| 4| 9| 9| 8| 5| 3| 9| 0| 0| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    25 MG/KG                               | 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |    X  X  X                                         X        X            |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Leukemia Mononuclear                 |    X  X  X        X                 X              X  X     X     X      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  19                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 6|                             |            |
                             DAY ON TEST   | 3| 2| 6| 5| 5| 3| 3| 0| 9| 5| 2| 2| 2| 7| 6|                             |            |
                                           | 0| 9| 8| 8| 8| 0| 0| 9| 2| 8| 9| 9| 9| 2| 1|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|                             |     A      |
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               |       +              +  +        M     +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  |       +              +  +              +  +                              |  24        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  |       +              +  +              +  +                              |  26        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 |       +              +  +              +  +                              |  28        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small                         |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  |       +              +  +              +  +                              |  24        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                |       +              +  +              +  +                              |  23        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 | X                    X                    X                              |         15 |
                                            __________________________________________________________________________|____________|
   Mesentery                               | +     +                                   +                              |  13        |
      Leukemia Mononuclear                 |                                           X                              |          5 |
                                            __________________________________________________________________________|____________|
   Pancreas                                |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Pharynx                                 |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         |       +              +  +              +  +                              |  26        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach                                 |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    |       +              +  +              +  +                              |  28        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      |       +              +  +              +  +                              |  28        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
      Squamous Cell Papilloma              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                                          |   3        |
      Pulp, Leukemia Mononuclear           |                                                                          |          2 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   |       +              +  +              +  +                              |  28        |
      Leukemia Mononuclear                 |                                           X                              |          7 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 | X                                         X                              |          9 |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 | X                                         X                              |          8 |
      Pheochromocytoma Malignant           |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  20                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 6|                             |            |
                             DAY ON TEST   | 3| 2| 6| 5| 5| 3| 3| 0| 9| 5| 2| 2| 2| 7| 6|                             |            |
                                           | 0| 9| 8| 8| 8| 0| 0| 9| 2| 8| 9| 9| 9| 2| 1|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|                             |     A      |
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Pheochromocytoma Complex             | X                                                                        |          1 |
      Bilateral, Pheochromocytoma Benign   |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       |       M           M  +  +        M     M  +                              |  22        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +        +  +  +  +     +  +  +  +  +                              |  54        |
      Leukemia Mononuclear                 |                      X                                                   |          1 |
      Pars Distalis, Adenoma               | X              X        X     X  X     X                                 |         21 |
      Pars Distalis, Carcinoma             |                                                                          |          1 |
      Pars Distalis, Leukemia Mononuclear  |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +        +  +  +  +     +  +  +  +  +                              |  54        |
      C-Cell, Adenoma                      |                                                                          |          3 |
      C-Cell, Carcinoma                    |                      X                                                   |          1 |
      Follicular Cell, Adenocarcinoma      |       X                                                                  |          1 |
      Follicular Cell, Adenoma             |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          |       +              +  +        +     +  +                              |  24        |
      Adenoma                              |                                  X                                       |          3 |
      Leukemia Mononuclear                 |                                           X                              |          2 |
                                            __________________________________________________________________________|____________|
   Ovary                                   |       +           +  +  +              +  +                              |  29        |
      Granulosa Cell Tumor Malignant       |                   X                                                      |          1 |
      Leukemia Mononuclear                 |                                                                          |          3 |
      Luteoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Leiomyosarcoma                       |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          2 |
      Polyp Stromal                        |                                                                          |          5 |
      Bilateral, Polyp Stromal             |                                                                          |          1 |
      Endometrium, Adenocarcinoma          |                                                                          |          1 |
      Endometrium, Sarcoma Stromal         |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |                      +                 +  +                              |  10        |
      Leukemia Mononuclear                 |                      X                    X                              |          8 |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             |       +              +  +              +  +                              |  28        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  21                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 6|                             |            |
                             DAY ON TEST   | 3| 2| 6| 5| 5| 3| 3| 0| 9| 5| 2| 2| 2| 7| 6|                             |            |
                                           | 0| 9| 8| 8| 8| 0| 0| 9| 2| 8| 9| 9| 9| 2| 1|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|                             |     A      |
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |                      X                    X                              |          7 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |       +              +  +              +  +                              |  28        |
      Mediastinal, Leukemia Mononuclear    |                      X                                                   |          3 |
      Pancreatic, Leukemia Mononuclear     |                      X                    X                              |          2 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  |       +              +  M              +  +                              |  26        |
      Leukemia Mononuclear                 |                      X                                                   |          5 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  |       +              +  +              +  +                              |  28        |
      Leukemia Mononuclear                 |                      X                    X                              |          8 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 | X                    X                    X                              |         15 |
                                            __________________________________________________________________________|____________|
   Thymus                                  |       +              +  +     M  M  M  +  +                              |  27        |
      Leukemia Mononuclear                 |                      X                                                   |          6 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Adenoma                              |                                                                          |          2 |
      Fibroadenoma                         |                   X              X     X  X                              |         22 |
                                            __________________________________________________________________________|____________|
   Skin                                    |       +              +  +     +        +  +                              |  30        |
      Basal Cell Adenoma                   |                                                                          |          1 |
      Keratoacanthoma                      |                               X                                          |          1 |
      Subcutaneous Tissue, Leukemia        |                                                                          |            |
          Mononuclear                      |                                                                          |          3 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    |       +              +  +              +  +                              |  28        |
      Cartilage, Adenocarcinoma, Extension,|                                                                          |            |
           Metastatic, Thyroid Gland       |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                      +                                                   |   2        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   |       +              +  +              +  +                              |  28        |
      Astrocytoma Malignant                |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          3 |
      Meninges, Leukemia Mononuclear       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                         +                                                |   7        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Meninges, Leukemia Mononuclear       |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  22                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 6|                             |            |
                             DAY ON TEST   | 3| 2| 6| 5| 5| 3| 3| 0| 9| 5| 2| 2| 2| 7| 6|                             |            |
                                           | 0| 9| 8| 8| 8| 0| 0| 9| 2| 8| 9| 9| 9| 2| 1|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|                             |     A      |
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    |       +              +  +              +  +                              |  29        |
      Alveolar/Bronchiolar Carcinoma       |                                                                          |          1 |
      Leukemia Mononuclear                 |                      X                                                   |          6 |
                                            __________________________________________________________________________|____________|
   Nose                                    |       +              +  +              +  +                              |  28        |
      Leukemia Mononuclear                 |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Trachea                                 |       +              +  +              +  +                              |  28        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 | X                    X                    X                              |         10 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         |       +              +  +              +  +                              |  27        |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 | X                    X                    X                              |         15 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  23                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 6| 4| 7| 6| 6| 4| 3| 7| 7| 7| 6| 5| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 2| 2| 9| 8| 5| 3| 3| 3| 5| 5| 1| 5| 3| 5| 4| 3| 3| 2| 5| 9| 3| 3| 2| 5| 5|             
                                           | 9| 9| 5| 7| 8| 1| 1| 0| 8| 8| 6| 8| 8| 8| 3| 0| 0| 9| 2| 8| 1| 0| 9| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  A  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +     +  +  +  +     A  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  M     +  +  +  M     A  M  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +     +  +  +  +     A  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
      Sarcoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  +     +  +  +  +     A  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Cystadenocarcinoma                   |                                                                          |             
      Leukemia Mononuclear                 |                                                       X                  |             
      Sarcoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 | X     X        X                 X  X              X  X     X            |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +              +           +  +                 +                  |             
      Leukemia Mononuclear                 |       X                          X  X                 X                  |             
      Pheochromocytoma Malignant,          |                                                                          |             
          Extension, Metastatic, Adrenal   |                                                                          |             
          Gland                            |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                X                                      X                  |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                X                                      X                  |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                                          |             
      Pulp, Leukemia Mononuclear           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X        X                    X                 X                  |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  24                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 6| 4| 7| 6| 6| 4| 3| 7| 7| 7| 6| 5| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 2| 2| 9| 8| 5| 3| 3| 3| 5| 5| 1| 5| 3| 5| 4| 3| 3| 2| 5| 9| 3| 3| 2| 5| 5|             
                                           | 9| 9| 5| 7| 8| 1| 1| 0| 8| 8| 6| 8| 8| 8| 3| 0| 0| 9| 2| 8| 1| 0| 9| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Adenoma                              |                               X                                          |             
      Leukemia Mononuclear                 | X     X        X                                      X                  |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X        X                                      X                  |             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              | X                 X                                   X     X            |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +     +  +  +  M     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                X                                                         |             
      Meningioma Malignant, Metastatic     |                                                                      X   |             
      Pars Distalis, Adenoma               |                   X                          X              X  X         |             
      Pars Distalis, Leukemia Mononuclear  |                                                       X                  |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
      C-Cell, Adenoma                      |                   X                                                      |             
      C-Cell, Carcinoma                    |    X           X                                                         |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +     +  +  +  +     +  M  +     M  +  +  +  M  +  +  +  +  +   |             
      Adenoma                              |    X                 X                          X           X  X         |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X        X                                                         |             
                                            __________________________________________________________________________|             
   Oviduct                                 |                                           +           +                  |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
      Polyp Stromal                        |       X                                                  X  X            |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
      Squamous Cell Carcinoma              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |       +        +                    +                 +           +      |             
      Leukemia Mononuclear                 |       X        X                    X                 X                  |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                X                    X                                    |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Axillary, Leukemia Mononuclear       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  25                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 6| 4| 7| 6| 6| 4| 3| 7| 7| 7| 6| 5| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 2| 2| 9| 8| 5| 3| 3| 3| 5| 5| 1| 5| 3| 5| 4| 3| 3| 2| 5| 9| 3| 3| 2| 5| 5|             
                                           | 9| 9| 5| 7| 8| 1| 1| 0| 8| 8| 6| 8| 8| 8| 3| 0| 0| 9| 2| 8| 1| 0| 9| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Deep Cervical, Leukemia Mononuclear  |                                                                          |             
      Inguinal, Leukemia Mononuclear       |                X                                                         |             
      Lumbar, Leukemia Mononuclear         |                                                       X                  |             
      Mediastinal, Leukemia Mononuclear    |       X                                                                  |             
      Pancreatic, Leukemia Mononuclear     |                                     X                 X                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  M     +  +  +  +     +  +  +     M  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X        X                    X                 X                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X        X                    X                 X                  |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 | X     X        X                 X  X              X  X     X            |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  M  +   |             
      Leukemia Mononuclear                 |                X                                      X                  |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +     +  +  +  +     +  +  +     M  +  +  +  +  +  +  +  +  +   |             
      Adenocarcinoma                       |                                              X                           |             
      Fibroadenoma                         |                X                 X           X  X  X     X     X         |             
      Fibroadenoma, Multiple               |                               X                                          |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Keratoacanthoma                      |                X  X                                                      |             
      Squamous Cell Papilloma              |                   X                                                      |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |                                                       X                  |             
      Subcutaneous Tissue, Sarcoma         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
      Pheochromocytoma Malignant,          |                                                                          |             
          Extension, Metastatic, Adrenal   |                                                                          |             
          Gland                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                               X                  |             
      Meninges, Leukemia Mononuclear       |                                                       X                  |             
      Meninges, Meningioma Malignant       |                                                                      X   |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                           +           +              +   |             
      Meninges, Leukemia Mononuclear       |                                                       X                  |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  26                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 6| 4| 7| 6| 6| 4| 3| 7| 7| 7| 6| 5| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 2| 2| 9| 8| 5| 3| 3| 3| 5| 5| 1| 5| 3| 5| 4| 3| 3| 2| 5| 9| 3| 3| 2| 5| 5|             
                                           | 9| 9| 5| 7| 8| 1| 1| 0| 8| 8| 6| 8| 8| 8| 3| 0| 0| 9| 2| 8| 1| 0| 9| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Alveolar/Bronchiolar Carcinoma       |                                                                X         |             
      Carcinoma, Metastatic, Thyroid Gland |                X                                                         |             
      Leukemia Mononuclear                 |       X        X                 X  X                 X                  |             
      Pheochromocytoma Malignant,          |                                                                          |             
          Metastatic, Adrenal Gland        |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X                                                                  |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                +     +   |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                      +   |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
      Carcinoma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |       X        X                 X  X              X  X                  |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +     +  +  M  +     +  +  +     +  +  +  +  +  M  +  +  +  +   |             
      Leukemia Mononuclear                 |                X                                      X                  |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 | X     X        X                 X  X              X  X     X            |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  27                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 6| 7| 6| 5| 4| 4|             
                             DAY ON TEST   | 2| 1| 1| 9| 3| 2| 0| 5| 5| 5| 3| 3| 3| 3| 9| 3| 3| 2| 2| 5| 0| 6| 8| 5| 5|             
                                           | 9| 4| 1| 4| 4| 9| 7| 8| 8| 8| 1| 0| 0| 0| 7| 0| 0| 9| 9| 8| 3| 9| 8| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
      Sarcoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +     +      |             
      Cystadenocarcinoma                   |             X                                                            |             
      Leukemia Mononuclear                 |                                                                          |             
      Sarcoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |    X     X     X  X                    X  X        X  X        X         |             
                                            __________________________________________________________________________|             
   Mesentery                               | M  +              +              +     +  +           +        +         |             
      Leukemia Mononuclear                 |                   X                    X  X                    X         |             
      Pheochromocytoma Malignant,          |                                                                          |             
          Extension, Metastatic, Adrenal   |                                                                          |             
          Gland                            |    X                                                                     |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                X                                               X         |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                        X           X           X         |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                           X                    X         |             
                                            __________________________________________________________________________|             
   Tooth                                   |                +  +                    +           +                     |             
      Pulp, Leukemia Mononuclear           |                X  X                    X           X                     |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                   X                    X  X        X           X         |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  28                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 6| 7| 6| 5| 4| 4|             
                             DAY ON TEST   | 2| 1| 1| 9| 3| 2| 0| 5| 5| 5| 3| 3| 3| 3| 9| 3| 3| 2| 2| 5| 0| 6| 8| 5| 5|             
                                           | 9| 4| 1| 4| 4| 9| 7| 8| 8| 8| 1| 0| 0| 0| 7| 0| 0| 9| 9| 8| 3| 9| 8| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Adenoma                              |                                                                          |             
      Leukemia Mononuclear                 |          X        X                    X  X        X           X         |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +  M  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                   X                    X  X        X           X         |             
      Pheochromocytoma Malignant           |    X                                                                     |             
      Pheochromocytoma Benign              |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  I  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                        X  X        X           X         |             
      Meningioma Malignant, Metastatic     |                                                                          |             
      Pars Distalis, Adenoma               | X        X                       X           X        X  X               |             
      Pars Distalis, Leukemia Mononuclear  |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
      C-Cell, Adenoma                      |          X                                                               |             
      C-Cell, Carcinoma                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Adenoma                              | X                                      X                       X         |             
      Leukemia Mononuclear                 |                                        X  X                              |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                X                       X           X           X         |             
                                            __________________________________________________________________________|             
   Oviduct                                 |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                           X        X           X         |             
      Polyp Stromal                        |                               X           X        X        X            |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
      Squamous Cell Carcinoma              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |          +     +  +                    +  +        +           +         |             
      Leukemia Mononuclear                 |          X     X  X                    X  X        X           X         |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X     X  X                    X  X        X           X         |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Axillary, Leukemia Mononuclear       |                                           X                              |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  29                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 6| 7| 6| 5| 4| 4|             
                             DAY ON TEST   | 2| 1| 1| 9| 3| 2| 0| 5| 5| 5| 3| 3| 3| 3| 9| 3| 3| 2| 2| 5| 0| 6| 8| 5| 5|             
                                           | 9| 4| 1| 4| 4| 9| 7| 8| 8| 8| 1| 0| 0| 0| 7| 0| 0| 9| 9| 8| 3| 9| 8| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Deep Cervical, Leukemia Mononuclear  |                                           X                              |             
      Inguinal, Leukemia Mononuclear       |                                           X                    X         |             
      Lumbar, Leukemia Mononuclear         |                                           X                              |             
      Mediastinal, Leukemia Mononuclear    |                                        X  X        X           X         |             
      Pancreatic, Leukemia Mononuclear     |                                           X        X                     |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +              +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X                             X  X        X           X         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +              +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X     X  X                    X  X        X  X        X         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |    X     X     X  X                    X  X        X  X        X         |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  M  M           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                           X        X           X         |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Adenocarcinoma                       |                                                                          |             
      Fibroadenoma                         |       X     X                       X        X  X        X        X      |             
      Fibroadenoma, Multiple               |                                                                          |             
      Leukemia Mononuclear                 |                                           X                    X         |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Keratoacanthoma                      |                                                                          |             
      Squamous Cell Papilloma              |                                                                          |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |                                           X                    X         |             
      Subcutaneous Tissue, Sarcoma         |       X                                                                  |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |    +                                                           +         |             
      Leukemia Mononuclear                 |                                                                X         |             
      Pheochromocytoma Malignant,          |                                                                          |             
          Extension, Metastatic, Adrenal   |                                                                          |             
          Gland                            |    X                                                                     |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
      Meninges, Leukemia Mononuclear       |                X                       X                                 |             
      Meninges, Meningioma Malignant       |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                +  +           +        +                       +         |             
      Meninges, Leukemia Mononuclear       |                X  X                    X                       X         |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  30                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 6| 7| 6| 5| 4| 4|             
                             DAY ON TEST   | 2| 1| 1| 9| 3| 2| 0| 5| 5| 5| 3| 3| 3| 3| 9| 3| 3| 2| 2| 5| 0| 6| 8| 5| 5|             
                                           | 9| 4| 1| 4| 4| 9| 7| 8| 8| 8| 1| 0| 0| 0| 7| 0| 0| 9| 9| 8| 3| 9| 8| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Alveolar/Bronchiolar Carcinoma       |                                                                          |             
      Carcinoma, Metastatic, Thyroid Gland |                                                                          |             
      Leukemia Mononuclear                 |          X        X                    X  X        X           X         |             
      Pheochromocytoma Malignant,          |                                                                          |             
          Metastatic, Adrenal Gland        |    X                                                                     |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                X  X                    X           X           X         |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |          +                                                        +      |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
      Carcinoma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X        X                    X  X        X           X         |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | M  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X                             X  X        X           X         |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |    X     X     X  X                    X  X        X  X        X         |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  31                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 7| 5| 3| 2| 2| 2| 9| 3| 3| 3| 3| 9|                             |            |
                                           | 1| 0| 9| 6| 8| 0| 9| 9| 9| 0| 1| 1| 0| 0| 2|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|                             |     A      |
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  53        |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  51        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small                         | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |                                           X                              |          3 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  53        |
      Leukemia Mononuclear                 |                         X                                                |          3 |
      Sarcoma                              |                                     X                                    |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  51        |
      Cystadenocarcinoma                   |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Sarcoma                              |                                     X                                    |          1 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |          X              X     X        X  X                              |         22 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |       +           +           +           +                              |  16        |
      Leukemia Mononuclear                 |                                                                          |          8 |
      Pheochromocytoma Malignant,          |                                                                          |            |
          Extension, Metastatic, Adrenal   |                                                                          |            |
          Gland                            |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |                                                                          |          4 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |                                                                          |          4 |
                                            __________________________________________________________________________|____________|
   Stomach                                 | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Leukemia Mononuclear                 |          X                                X                              |          4 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Leukemia Mononuclear                 |                                                                          |          4 |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                         +                                                |   5        |
      Pulp, Leukemia Mononuclear           |                         X                                                |          5 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  32                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 7| 5| 3| 2| 2| 2| 9| 3| 3| 3| 3| 9|                             |            |
                                           | 1| 0| 9| 6| 8| 0| 9| 9| 9| 0| 1| 1| 0| 0| 2|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|                             |     A      |
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 CARDIOVASCULAR SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |          X              X              X  X                              |         13 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Adenoma                              |                                                                          |          1 |
      Leukemia Mononuclear                 |          X              X              X  X                              |         14 |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Leukemia Mononuclear                 |          X              X              X  X                              |         12 |
      Pheochromocytoma Malignant           |                                                                          |          1 |
      Pheochromocytoma Benign              |                                                                          |          4 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Leukemia Mononuclear                 |                         X                                                |          1 |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Leukemia Mononuclear                 |                         X              X  X                              |          8 |
      Meningioma Malignant, Metastatic     |                                                                          |          1 |
      Pars Distalis, Adenoma               |                X  X           X  X     X  X                              |         16 |
      Pars Distalis, Leukemia Mononuclear  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      C-Cell, Adenoma                      |          X                    X  X                                       |          5 |
      C-Cell, Carcinoma                    |    X                                                                     |          3 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  52        |
      Adenoma                              |                X                                                         |          9 |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |                         X              X                                 |          8 |
                                            __________________________________________________________________________|____________|
   Oviduct                                 |                                                                          |   2        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |                                                                          |          4 |
      Polyp Stromal                        |                         X        X                                       |          9 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  33                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 7| 5| 3| 2| 2| 2| 9| 3| 3| 3| 3| 9|                             |            |
                                           | 1| 0| 9| 6| 8| 0| 9| 9| 9| 0| 1| 1| 0| 0| 2|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|                             |     A      |
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                  +                                       |   1        |
      Squamous Cell Carcinoma              |                                  X                                       |          1 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |          +     +        +  +           +  +                              |  18        |
      Leukemia Mononuclear                 |          X              X              X  X                              |         15 |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |          X                                X                              |         11 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Axillary, Leukemia Mononuclear       |                                                                          |          1 |
      Deep Cervical, Leukemia Mononuclear  |                                                                          |          1 |
      Inguinal, Leukemia Mononuclear       |                                                                          |          3 |
      Lumbar, Leukemia Mononuclear         |                                                                          |          2 |
      Mediastinal, Leukemia Mononuclear    |                                        X                                 |          6 |
      Pancreatic, Leukemia Mononuclear     |                                                                          |          4 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  52        |
      Leukemia Mononuclear                 |          X              X              X  X                              |         13 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Leukemia Mononuclear                 |          X              X              X  X                              |         16 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |          X              X     X        X  X                              |         22 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +     +  +  +  +  +  M  +  +  +  +                              |  51        |
      Leukemia Mononuclear                 |          X              X              X  X                              |          9 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Adenocarcinoma                       |                                                                          |          1 |
      Fibroadenoma                         | X              X  X  X  X        X     X                                 |         21 |
      Fibroadenoma, Multiple               |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Keratoacanthoma                      |                                                                          |          2 |
      Squamous Cell Papilloma              |                                                                          |          1 |
      Subcutaneous Tissue, Leukemia        |                                                                          |            |
          Mononuclear                      |          X                                                               |          4 |
      Subcutaneous Tissue, Sarcoma         |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  34                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 7| 5| 3| 2| 2| 2| 9| 3| 3| 3| 3| 9|                             |            |
                                           | 1| 0| 9| 6| 8| 0| 9| 9| 9| 0| 1| 1| 0| 0| 2|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|                             |     A      |
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   2        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Pheochromocytoma Malignant,          |                                                                          |            |
          Extension, Metastatic, Adrenal   |                                                                          |            |
          Gland                            |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |                                                                          |          3 |
      Meninges, Leukemia Mononuclear       |                         X                                                |          4 |
      Meninges, Meningioma Malignant       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |          +              +              +  +                              |  12        |
      Meninges, Leukemia Mononuclear       |          X              X              X                                 |          8 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Alveolar/Bronchiolar Carcinoma       |                                                                          |          1 |
      Carcinoma, Metastatic, Thyroid Gland |                                                                          |          1 |
      Leukemia Mononuclear                 |          X              X              X  X                              |         15 |
      Pheochromocytoma Malignant,          |                                                                          |            |
          Metastatic, Adrenal Gland        |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |                                                                          |          6 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |                                                                          |          2 |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                            +  +                                          |   6        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                            +                                             |   1        |
      Carcinoma                            |                            X                                             |          1 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Leukemia Mononuclear                 |          X              X              X  X                              |         16 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +     +  +  +  +  +  +  +  +  +  M                              |  51        |
      Leukemia Mononuclear                 |          X                                                               |          8 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  35                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 7| 5| 3| 2| 2| 2| 9| 3| 3| 3| 3| 9|                             |            |
                                           | 1| 0| 9| 6| 8| 0| 9| 9| 9| 0| 1| 1| 0| 0| 2|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|                             |     A      |
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |          X              X     X        X  X                              |         22 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  36                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 7| 4| 2| 7| 7| 7| 6| 7| 7| 6| 6| 4| 7| 7| 6| 5| 4|             
                             DAY ON TEST   | 3| 3| 3| 6| 5| 3| 3| 3| 3| 5| 7| 3| 3| 3| 4| 3| 3| 7| 3| 8| 3| 3| 6| 6| 5|             
                                           | 1| 1| 1| 7| 9| 2| 2| 2| 1| 9| 3| 2| 1| 1| 6| 2| 0| 6| 7| 3| 2| 1| 5| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  A  +  +  +  +  A  +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  A  +   |             
      Leukemia Mononuclear                 |          X                                            X                  |             
      Serosa, Histiocytic Sarcoma,         |                                                                          |             
          Metastatic                       |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |          X              X                                                |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  A  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  A  +   |             
      Leukemia Mononuclear                 |                                                       X     X            |             
      Serosa, Ileum, Jejunum, Histiocytic  |                                                                          |             
          Sarcoma, Metastatic              |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  A  +  +  +  +  A  +   |             
      Leukemia Mononuclear                 |          X     X                                                         |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +     +  M  +  +     A  +  +  +  +  +  +  A  +  +  +  +  A  +   |             
      Leiomyosarcoma                       |                                                          X               |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hepatocellular Adenoma               |                                              X                           |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leiomyosarcoma, Metastatic,          |                                                                          |             
          Intestine Small                  |                                                          X               |             
      Leukemia Mononuclear                 | X  X     X     X     X  X              X  X           X     X  X     X   |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                  +        +              +               |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leiomyosarcoma, Extension,           |                                                                          |             
          Metastatic, Intestine Small      |                                                          X               |             
      Leukemia Mononuclear                 |                                                                          |             
      Mesothelioma Malignant, Metastatic   |                                  X                                       |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  A  +   |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |                                           X           X                  |             
                                            __________________________________________________________________________|             
   Pharynx                                 |                                                                          |             
      Palate, Carcinoma, Extension,        |                                                                          |             
          Metastatic, Zymbal's Gland       |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  M  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X     X        X   |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X     X            |             
      Serosa, Glandular, Histiocytic       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  37                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 7| 4| 2| 7| 7| 7| 6| 7| 7| 6| 6| 4| 7| 7| 6| 5| 4|             
                             DAY ON TEST   | 3| 3| 3| 6| 5| 3| 3| 3| 3| 5| 7| 3| 3| 3| 4| 3| 3| 7| 3| 8| 3| 3| 6| 6| 5|             
                                           | 1| 1| 1| 7| 9| 2| 2| 2| 1| 9| 3| 2| 1| 1| 6| 2| 0| 6| 7| 3| 2| 1| 5| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
          Sarcoma, Metastatic              |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                             X            |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
      Squamous Cell Papilloma              |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |                +                          +           +                  |             
      Pulp, Leukemia Mononuclear           |                X                          X           X                  |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                X                          X           X     X        X   |             
      Endocardium, Schwannoma NOS          |                X                                      X                  |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +  +     +  +  +  +  +  +     +  +  +  +  +  +  +   |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |          X     X                          X           X     X        X   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                X                          X           X     X        X   |             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |                      X                 X        X                        |             
      Bilateral, Pheochromocytoma Benign   |                                                             X            |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                             X            |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +     +  +  +  +     M  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                             X            |             
      Pars Distalis, Adenoma               | X                                               X                        |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |                                                       X              X   |             
      C-Cell, Adenoma                      |                                              X        X        X         |             
      C-Cell, Carcinoma                    |                                  X                 X                     |             
      Follicular Cell, Adenocarcinoma      |                                                                          |             
      Follicular Cell, Adenoma             |       X                                                                  |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  M  +   |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  38                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 7| 4| 2| 7| 7| 7| 6| 7| 7| 6| 6| 4| 7| 7| 6| 5| 4|             
                             DAY ON TEST   | 3| 3| 3| 6| 5| 3| 3| 3| 3| 5| 7| 3| 3| 3| 4| 3| 3| 7| 3| 8| 3| 3| 6| 6| 5|             
                                           | 1| 1| 1| 7| 9| 2| 2| 2| 1| 9| 3| 2| 1| 1| 6| 2| 0| 6| 7| 3| 2| 1| 5| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 | X                                                     X                  |             
      Mesothelioma Malignant, Metastatic   |                                  X                                       |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +     +  +  +  +     M  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Adenoma                              |       X        X                 X     X                    X            |             
      Carcinoma                            |                                  X                                       |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |          X                                            X                  |             
      Mesothelioma Malignant, Metastatic   |                                  X                                       |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X     X            |             
      Serosa, Histiocytic Sarcoma,         |                                                                          |             
          Metastatic                       |                                                                          |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X     X            |             
      Serosa, Histiocytic Sarcoma,         |                                                                          |             
          Metastatic                       |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  M  +   |             
      Leukemia Mononuclear                 |          X                                            X     X        X   |             
      Bilateral, Interstitial Cell, Adenoma| X     X        X  X  X  X           X  X  X  X     X  X     X  X         |             
      Interstitial Cell, Adenoma           |    X     X                       X                       X           X   |             
      Tunic, Histiocytic Sarcoma,          |                                                                          |             
          Metastatic                       |                                                                          |             
      Tunic, Mesothelioma Malignant        |                                  X                                       |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |          +     +     +                    +           +     +  +     +   |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |          X           X                    X           X     X  X     X   |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |          X                                X           X              X   |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Axillary, Leukemia Mononuclear       |          X                                                               |             
      Bronchial, Leukemia Mononuclear      |                                                                          |             
      Deep Cervical, Leukemia Mononuclear  |                                                                          |             
      Iliac, Leukemia Mononuclear          |                                                                          |             
      Inguinal, Leukemia Mononuclear       |                                        X                    X            |             
      Lumbar, Leukemia Mononuclear         |                                           X                              |             
      Mediastinal, Leukemia Mononuclear    |                X                                               X         |             
      Pancreatic, Leukemia Mononuclear     |                      X                    X           X                  |             
      Renal, Leukemia Mononuclear          |                      X                                      X            |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  M  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                       X              X     X        X   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +  +     M  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  39                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 7| 4| 2| 7| 7| 7| 6| 7| 7| 6| 6| 4| 7| 7| 6| 5| 4|             
                             DAY ON TEST   | 3| 3| 3| 6| 5| 3| 3| 3| 3| 5| 7| 3| 3| 3| 4| 3| 3| 7| 3| 8| 3| 3| 6| 6| 5|             
                                           | 1| 1| 1| 7| 9| 2| 2| 2| 1| 9| 3| 2| 1| 1| 6| 2| 0| 6| 7| 3| 2| 1| 5| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |          X     X     X                    X           X     X  X     X   |             
      Inguinal, Lumbar, Mediastinal,       |                                                                          |             
          Histiocytic Sarcoma, Metastatic  |                                                                          |             
      Mediastinal, Mandibular, Histiocytic |                                                                          |             
          Sarcoma, Metastatic              |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 | X  X     X     X     X  X              X  X           X     X  X     X   |             
      Capsule, Histiocytic Sarcoma,        |                                                                          |             
          Metastatic                       |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  +  +     +  +  M  +     +  +  +  +  +  +  M  +  +  +  +  M  +  +   |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |          X                             X              X     X        X   |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  M     +  +  +  +     M  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Adenocarcinoma                       |    X                                                                     |             
      Adenoma                              |                   X                                                      |             
      Fibroadenoma                         |       X                                                                  |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |                                                             X            |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Keratoacanthoma                      |          X                                                               |             
      Hair Follicle, Leukemia Mononuclear  |                                                                          |             
      Posterior, Leukemia Mononuclear      |                                                                          |             
      Subcutaneous Tissue, Fibroma         |                                                                          |             
      Subcutaneous Tissue, Fibrosarcoma    |                                                                          |             
      Subcutaneous Tissue, Histiocytic     |                                                                          |             
          Sarcoma                          |                                                                          |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |          X                                                  X            |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Vertebra, Leukemia Mononuclear       |                                                                          |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |          +                                                               |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |          X                                                               |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                       X                  |             
      Meninges, Leukemia Mononuclear       |                                           X           X     X            |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |          +                                               +  +        +   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  40                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 7| 4| 2| 7| 7| 7| 6| 7| 7| 6| 6| 4| 7| 7| 6| 5| 4|             
                             DAY ON TEST   | 3| 3| 3| 6| 5| 3| 3| 3| 3| 5| 7| 3| 3| 3| 4| 3| 3| 7| 3| 8| 3| 3| 6| 6| 5|             
                                           | 1| 1| 1| 7| 9| 2| 2| 2| 1| 9| 3| 2| 1| 1| 6| 2| 0| 6| 7| 3| 2| 1| 5| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
      Meninges, Leukemia Mononuclear       |          X                                                  X            |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Alveolar/Bronchiolar Adenoma         |                                                                          |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |          X     X     X                 X  X           X     X  X     X   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |          X                                            X                  |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +     +  +  +  +     +  +     +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |          +                                                               |             
      Canal, Carcinoma, Extension,         |                                                                          |             
          Metastatic, Zymbal's Gland       |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |          +                                                           +   |             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |          +                                                               |             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
      Carcinoma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Leukemia Mononuclear                 |          X     X                          X           X     X  X     X   |             
      Capsule, Histiocytic Sarcoma,        |                                                                          |             
          Metastatic                       |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  M  +   |             
      Leukemia Mononuclear                 |                                                             X            |             
      Serosa, Histiocytic Sarcoma,         |                                                                          |             
          Metastatic                       |                                                                          |             
      Serosa, Mesothelioma Malignant,      |                                                                          |             
          Metastatic                       |                                  X                                       |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 | X  X     X     X     X  X              X  X           X     X  X     X   |             
      Mesothelioma Malignant               |                                  X                                       |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  41                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 3| 7| 7| 7| 6| 7| 7| 5| 4| 4| 7| 7| 7| 7| 6| 7| 7| 7| 5| 3| 7| 6| 6| 4| 4|             
                             DAY ON TEST   | 6| 3| 3| 3| 0| 3| 3| 9| 5| 5| 3| 3| 2| 1| 0| 3| 3| 1| 9| 8| 3| 8| 1| 5| 5|             
                                           | 7| 2| 1| 1| 2| 1| 1| 6| 9| 9| 1| 1| 9| 5| 2| 2| 2| 3| 3| 1| 1| 3| 6| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
    VEHICLE                                | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  A  +  +  +        +  +  +  A  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  A  +  +  +        +  +  +  A  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                          X               |             
      Serosa, Histiocytic Sarcoma,         |                                                                          |             
          Metastatic                       |                                           X                              |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                          X               |             
      Serosa, Ileum, Jejunum, Histiocytic  |                                                                          |             
          Sarcoma, Metastatic              |                                           X                              |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  A  +  +  +        +  +  +  A     +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                          X               |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  A  +  +  M        +  +  +  A     +  +  +  +  A  +  +  +      |             
      Leiomyosarcoma                       |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Hepatocellular Adenoma               |                                                 X                        |             
      Histiocytic Sarcoma, Metastatic      |                                           X                              |             
      Leiomyosarcoma, Metastatic,          |                                                                          |             
          Intestine Small                  |                                                                          |             
      Leukemia Mononuclear                 | X  X     X     X  X                             X        X  X  X         |             
                                            __________________________________________________________________________|             
   Mesentery                               | +        +                                +                              |             
      Histiocytic Sarcoma, Metastatic      |                                           X                              |             
      Leiomyosarcoma, Extension,           |                                                                          |             
          Metastatic, Intestine Small      |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
      Mesothelioma Malignant, Metastatic   |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Histiocytic Sarcoma, Metastatic      |                                           X                              |             
      Leukemia Mononuclear                 |                                                          X               |             
                                            __________________________________________________________________________|             
   Pharynx                                 |                                                                          |             
      Palate, Carcinoma, Extension,        |                                                                          |             
          Metastatic, Zymbal's Gland       |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                X                                                         |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                          |             
      Serosa, Glandular, Histiocytic       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  42                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 3| 7| 7| 7| 6| 7| 7| 5| 4| 4| 7| 7| 7| 7| 6| 7| 7| 7| 5| 3| 7| 6| 6| 4| 4|             
                             DAY ON TEST   | 6| 3| 3| 3| 0| 3| 3| 9| 5| 5| 3| 3| 2| 1| 0| 3| 3| 1| 9| 8| 3| 8| 1| 5| 5|             
                                           | 7| 2| 1| 1| 2| 1| 1| 6| 9| 9| 1| 1| 9| 5| 2| 2| 2| 3| 3| 1| 1| 3| 6| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
    VEHICLE                                | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
          Sarcoma, Metastatic              |                                           X                              |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +        +  +  +  +     +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Tongue                                  |                      +                                +                  |             
      Squamous Cell Papilloma              |                                                       X                  |             
                                            __________________________________________________________________________|             
   Tooth                                   |          +                                               +     +         |             
      Pulp, Leukemia Mononuclear           |          X                                               X     X         |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X     X                                         X  X  X         |             
      Endocardium, Schwannoma NOS          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Histiocytic Sarcoma, Metastatic      |                                           X                              |             
      Leukemia Mononuclear                 |          X     X                                         X  X  X         |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X     X                                         X  X  X         |             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |       X  X                                      X                 X      |             
      Bilateral, Pheochromocytoma Benign   |                                        X                                 |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Adenoma                              |                                        X                                 |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                          X     X         |             
      Pars Distalis, Adenoma               |    X  X     X     X                       X  X     X                     |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
      C-Cell, Adenoma                      |                X                                                         |             
      C-Cell, Carcinoma                    |                                                                          |             
      Follicular Cell, Adenocarcinoma      |    X                                   X                                 |             
      Follicular Cell, Adenoma             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Histiocytic Sarcoma, Metastatic      |                                           X                              |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  43                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 3| 7| 7| 7| 6| 7| 7| 5| 4| 4| 7| 7| 7| 7| 6| 7| 7| 7| 5| 3| 7| 6| 6| 4| 4|             
                             DAY ON TEST   | 6| 3| 3| 3| 0| 3| 3| 9| 5| 5| 3| 3| 2| 1| 0| 3| 3| 1| 9| 8| 3| 8| 1| 5| 5|             
                                           | 7| 2| 1| 1| 2| 1| 1| 6| 9| 9| 1| 1| 9| 5| 2| 2| 2| 3| 3| 1| 1| 3| 6| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
    VEHICLE                                | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
      Mesothelioma Malignant, Metastatic   |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | M  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Adenoma                              |    X  X                                         X           X     X      |             
      Carcinoma                            |                                                                          |             
      Histiocytic Sarcoma, Metastatic      |                                           X                              |             
      Leukemia Mononuclear                 |                                                                X         |             
      Mesothelioma Malignant, Metastatic   |                                                                          |             
                                            __________________________________________________________________________|             
   Prostate                                | +  M  +  +  +  +  +  +        M  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                          |             
      Serosa, Histiocytic Sarcoma,         |                                                                          |             
          Metastatic                       |                                           X                              |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  M  +  +  +  +  +  +        M  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                X                                               X         |             
      Serosa, Histiocytic Sarcoma,         |                                                                          |             
          Metastatic                       |                                           X                              |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                          X     X         |             
      Bilateral, Interstitial Cell, Adenoma|       X        X  X  X        X  X  X  X  X  X     X  X     X  X  X      |             
      Interstitial Cell, Adenoma           |          X                                      X                        |             
      Tunic, Histiocytic Sarcoma,          |                                                                          |             
          Metastatic                       |                                           X                              |             
      Tunic, Mesothelioma Malignant        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   | +  +  +  +     +                          +              +  +  +         |             
      Histiocytic Sarcoma, Metastatic      |                                           X                              |             
      Leukemia Mononuclear                 | X        X     X                                         X     X         |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |                                                          X  X  X         |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Axillary, Leukemia Mononuclear       |                                                                          |             
      Bronchial, Leukemia Mononuclear      |    X                                                                     |             
      Deep Cervical, Leukemia Mononuclear  |                                                                          |             
      Iliac, Leukemia Mononuclear          |                                                                          |             
      Inguinal, Leukemia Mononuclear       |                                                                          |             
      Lumbar, Leukemia Mononuclear         |                                                                X         |             
      Mediastinal, Leukemia Mononuclear    |          X                                                  X            |             
      Pancreatic, Leukemia Mononuclear     |                   X                             X              X         |             
      Renal, Leukemia Mononuclear          |    X                                                                     |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +     +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X     X                                X        X     X         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +     +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  44                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 3| 7| 7| 7| 6| 7| 7| 5| 4| 4| 7| 7| 7| 7| 6| 7| 7| 7| 5| 3| 7| 6| 6| 4| 4|             
                             DAY ON TEST   | 6| 3| 3| 3| 0| 3| 3| 9| 5| 5| 3| 3| 2| 1| 0| 3| 3| 1| 9| 8| 3| 8| 1| 5| 5|             
                                           | 7| 2| 1| 1| 2| 1| 1| 6| 9| 9| 1| 1| 9| 5| 2| 2| 2| 3| 3| 1| 1| 3| 6| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
    VEHICLE                                | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 | X        X                                               X  X  X         |             
      Inguinal, Lumbar, Mediastinal,       |                                                                          |             
          Histiocytic Sarcoma, Metastatic  |                                           X                              |             
      Mediastinal, Mandibular, Histiocytic |                                                                          |             
          Sarcoma, Metastatic              |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 | X  X     X     X  X                             X        X  X  X         |             
      Capsule, Histiocytic Sarcoma,        |                                                                          |             
          Metastatic                       |                                           X                              |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  M  M  +  +  M  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |                                                          X     X         |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  +  +  M  +  +  +  M        +  +  +  +  +  +  +  +  +  +  +  M  +      |             
      Adenocarcinoma                       |                                                                          |             
      Adenoma                              |                                                                          |             
      Fibroadenoma                         |                X                                X                        |             
      Histiocytic Sarcoma, Metastatic      |                                           X                              |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Keratoacanthoma                      |                                                             X            |             
      Hair Follicle, Leukemia Mononuclear  |                                                                X         |             
      Posterior, Leukemia Mononuclear      |                                                          X               |             
      Subcutaneous Tissue, Fibroma         |                      X                                                   |             
      Subcutaneous Tissue, Fibrosarcoma    |                                           X                              |             
      Subcutaneous Tissue, Histiocytic     |                                                                          |             
          Sarcoma                          |                                           X                              |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |                                                          X     X         |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Vertebra, Leukemia Mononuclear       |                                                                          |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                     +     +                              |             
      Histiocytic Sarcoma, Metastatic      |                                           X                              |             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                          X     X         |             
      Meninges, Leukemia Mononuclear       |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             | +                                               +        +     +         |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  45                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 3| 7| 7| 7| 6| 7| 7| 5| 4| 4| 7| 7| 7| 7| 6| 7| 7| 7| 5| 3| 7| 6| 6| 4| 4|             
                             DAY ON TEST   | 6| 3| 3| 3| 0| 3| 3| 9| 5| 5| 3| 3| 2| 1| 0| 3| 3| 1| 9| 8| 3| 8| 1| 5| 5|             
                                           | 7| 2| 1| 1| 2| 1| 1| 6| 9| 9| 1| 1| 9| 5| 2| 2| 2| 3| 3| 1| 1| 3| 6| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
    VEHICLE                                | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                                                          X     X         |             
      Meninges, Leukemia Mononuclear       |                                                 X                        |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Alveolar/Bronchiolar Adenoma         |                                                                          |             
      Histiocytic Sarcoma, Metastatic      |                                           X                              |             
      Leukemia Mononuclear                 | X  X     X     X  X                                      X  X  X         |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +     +  +      |             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                                          |             
      Canal, Carcinoma, Extension,         |                                                                          |             
          Metastatic, Zymbal's Gland       |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                      +                                            +      |             
      Carcinoma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X                                               X  X  X         |             
      Capsule, Histiocytic Sarcoma,        |                                                                          |             
          Metastatic                       |                                           X                              |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  M  +  +  A  +  +  +        M  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |                                                                X         |             
      Serosa, Histiocytic Sarcoma,         |                                                                          |             
          Metastatic                       |                                           X                              |             
      Serosa, Mesothelioma Malignant,      |                                                                          |             
          Metastatic                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Histiocytic Sarcoma                  |                                           X                              |             
      Leukemia Mononuclear                 | X  X     X     X  X                             X        X  X  X         |             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  46                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |     A      |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |     L      |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         | +  +  +  +     +  A  +  +     +  +  +  +                                 |  53        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +     +  A  +  +     +  +  +  +                                 |  50        |
      Leukemia Mononuclear                 |                         X           X                                    |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +     +  A  +  +     +  +  +  +                                 |  51        |
      Leukemia Mononuclear                 |    X                                X                                    |          5 |
      Serosa, Histiocytic Sarcoma,         |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +     +  A  +  +     +  +  +  +                                 |  53        |
      Leukemia Mononuclear                 |    X                    X           X                                    |          5 |
                                            __________________________________________________________________________|____________|
   Intestine Small                         | +  +  +  +     +  A  +  +     +  +  +  +                                 |  52        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +     +  A  +  +     +  +  +  +                                 |  52        |
      Leukemia Mononuclear                 |                         X           X                                    |          5 |
      Serosa, Ileum, Jejunum, Histiocytic  |                                                                          |            |
          Sarcoma, Metastatic              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +     +  A  A  +     +  +  +  +                                 |  48        |
      Leukemia Mononuclear                 |                                     X                                    |          4 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +     +  M  A  +     +  +  +  +                                 |  44        |
      Leiomyosarcoma                       |                                                                          |          1 |
      Leukemia Mononuclear                 |                                     X                                    |          1 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Hepatocellular Adenoma               |                      X                                                   |          3 |
      Histiocytic Sarcoma, Metastatic      |                                        X                                 |          2 |
      Leiomyosarcoma, Metastatic,          |                                                                          |            |
          Intestine Small                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X              X     X     X  X  X                                    |         27 |
                                            __________________________________________________________________________|____________|
   Mesentery                               | +  +                    +     +     +  +                                 |  12        |
      Histiocytic Sarcoma, Metastatic      |                                        X                                 |          2 |
      Leiomyosarcoma, Extension,           |                                                                          |            |
          Metastatic, Intestine Small      |                                                                          |          1 |
      Leukemia Mononuclear                 |    X                    X           X                                    |          3 |
      Mesothelioma Malignant, Metastatic   |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Histiocytic Sarcoma, Metastatic      |                                        X                                 |          2 |
      Leukemia Mononuclear                 |    X                                X                                    |          5 |
                                            __________________________________________________________________________|____________|
   Pharynx                                 |          +                                                               |   1        |
      Palate, Carcinoma, Extension,        |                                                                          |            |
          Metastatic, Zymbal's Gland       |          X                                                               |          1 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  47                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |     A      |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |     L      |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |                                     X                                    |          5 |
                                            __________________________________________________________________________|____________|
   Stomach                                 | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |    X                                X                                    |          4 |
      Serosa, Glandular, Histiocytic       |                                                                          |            |
          Sarcoma, Metastatic              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |                         X           X                                    |          3 |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   2        |
      Squamous Cell Papilloma              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Tooth                                   |    +                                +                                    |   8        |
      Pulp, Leukemia Mononuclear           |    X                                X                                    |          8 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |    X                    X           X                                    |         13 |
      Endocardium, Schwannoma NOS          |                                                                          |          2 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Histiocytic Sarcoma, Metastatic      |                                                                          |          1 |
      Leukemia Mononuclear                 |    X                    X        X  X                                    |         15 |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |    X                    X        X  X                                    |         14 |
      Pheochromocytoma Malignant           |                               X                                          |          1 |
      Pheochromocytoma Benign              |          X           X                                                   |          9 |
      Bilateral, Pheochromocytoma Benign   |    X           X                                                         |          4 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +     +  +  +  +     +  +  M  +                                 |  54        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |    X                    X           X                                    |          6 |
      Pars Distalis, Adenoma               |    X  X  X                             X                                 |         13 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Histiocytic Sarcoma, Metastatic      |                                        X                                 |          1 |
      Leukemia Mononuclear                 |    X                                X                                    |          4 |
      C-Cell, Adenoma                      | X                                                                        |          5 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  48                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |     A      |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |     L      |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      C-Cell, Carcinoma                    |                                                                          |          2 |
      Follicular Cell, Adenocarcinoma      |                                                                          |          2 |
      Follicular Cell, Adenoma             |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  M  +     +  +  +  +     +  +  +  +                                 |  53        |
      Histiocytic Sarcoma, Metastatic      |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          2 |
      Mesothelioma Malignant, Metastatic   |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Adenoma                              |                               X                                          |         11 |
      Carcinoma                            |                                                                          |          1 |
      Histiocytic Sarcoma, Metastatic      |                                                                          |          1 |
      Leukemia Mononuclear                 |    X                                X                                    |          5 |
      Mesothelioma Malignant, Metastatic   |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Leukemia Mononuclear                 |    X                                X                                    |          4 |
      Serosa, Histiocytic Sarcoma,         |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Leukemia Mononuclear                 |    X                                                                     |          5 |
      Serosa, Histiocytic Sarcoma,         |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |                         X           X                                    |          8 |
      Bilateral, Interstitial Cell, Adenoma| X  X     X     X     X  X     X     X                                    |         37 |
      Interstitial Cell, Adenoma           |       X                          X                                       |          9 |
      Tunic, Histiocytic Sarcoma,          |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
      Tunic, Mesothelioma Malignant        |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |    +              +     +        +  +                                    |  22        |
      Histiocytic Sarcoma, Metastatic      |                                                                          |          1 |
      Leukemia Mononuclear                 |    X              X     X        X  X                                    |         17 |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  49                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |     A      |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |     L      |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Histiocytic Sarcoma, Metastatic      |                                        X                                 |          1 |
      Leukemia Mononuclear                 |    X              X     X           X                                    |         11 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Axillary, Leukemia Mononuclear       |                                                                          |          1 |
      Bronchial, Leukemia Mononuclear      |                                                                          |          1 |
      Deep Cervical, Leukemia Mononuclear  |    X                                                                     |          1 |
      Iliac, Leukemia Mononuclear          |                                     X                                    |          1 |
      Inguinal, Leukemia Mononuclear       |    X                                                                     |          3 |
      Lumbar, Leukemia Mononuclear         |    X              X                                                      |          4 |
      Mediastinal, Leukemia Mononuclear    |    X              X                                                      |          6 |
      Pancreatic, Leukemia Mononuclear     |    X              X                 X                                    |          9 |
      Renal, Leukemia Mononuclear          |                                     X                                    |          4 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +     +  +  +  +     +  +  +                                    |  52        |
      Leukemia Mononuclear                 |    X              X     X           X                                    |         15 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Leukemia Mononuclear                 |    X              X     X        X  X                                    |         18 |
      Inguinal, Lumbar, Mediastinal,       |                                                                          |            |
          Histiocytic Sarcoma, Metastatic  |                                                                          |          1 |
      Mediastinal, Mandibular, Histiocytic |                                                                          |            |
          Sarcoma, Metastatic              |                                        X                                 |          1 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Histiocytic Sarcoma, Metastatic      |                                        X                                 |          1 |
      Leukemia Mononuclear                 |    X           X  X     X     X  X  X                                    |         28 |
      Capsule, Histiocytic Sarcoma,        |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +     +  +  +  +     M  +  +  +                                 |  46        |
      Histiocytic Sarcoma, Metastatic      |                                        X                                 |          1 |
      Leukemia Mononuclear                 |    X                    X           X                                    |         10 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  49        |
      Adenocarcinoma                       |                                                                          |          1 |
      Adenoma                              |                                                                          |          1 |
      Fibroadenoma                         |                                                                          |          3 |
      Histiocytic Sarcoma, Metastatic      |                                                                          |          1 |
      Leukemia Mononuclear                 |    X                                                                     |          2 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Keratoacanthoma                      |                                                                          |          2 |
      Hair Follicle, Leukemia Mononuclear  |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  50                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |     A      |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |     L      |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Posterior, Leukemia Mononuclear      |                                                                          |          1 |
      Subcutaneous Tissue, Fibroma         |                                                                          |          1 |
      Subcutaneous Tissue, Fibrosarcoma    |                                                                          |          1 |
      Subcutaneous Tissue, Histiocytic     |                                                                          |            |
          Sarcoma                          |                                        X                                 |          2 |
      Subcutaneous Tissue, Leukemia        |                                                                          |            |
          Mononuclear                      |    X                                X                                    |          6 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Vertebra, Leukemia Mononuclear       |                                     X                                    |          1 |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                     +                                    |   4        |
      Histiocytic Sarcoma, Metastatic      |                                                                          |          1 |
      Leukemia Mononuclear                 |                                     X                                    |          2 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |    X                                X                                    |          5 |
      Meninges, Leukemia Mononuclear       |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |    +           +  +              +  +  M                                 |  13        |
      Leukemia Mononuclear                 |                                                                          |          2 |
      Meninges, Leukemia Mononuclear       |    X              X                 X                                    |          6 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  |          +                                                               |   1        |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Alveolar/Bronchiolar Adenoma         |                X                                                         |          1 |
      Histiocytic Sarcoma, Metastatic      |                                        X                                 |          2 |
      Leukemia Mononuclear                 |    X                    X        X  X                                    |         21 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |    X                                X                                    |          5 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Leukemia Mononuclear                 |                                     X                                    |          1 |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |          +                                                               |   2        |
      Canal, Carcinoma, Extension,         |                                                                          |            |
          Metastatic, Zymbal's Gland       |          X                                                               |          1 |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   2        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  51                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |     A      |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |     L      |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 SPECIAL SENSES SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                        +                                 |   2        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |          +                                                               |   3        |
      Carcinoma                            |          X                                                               |          1 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |    X              X     X        X  X                                    |         16 |
      Capsule, Histiocytic Sarcoma,        |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  51        |
      Leukemia Mononuclear                 |    X                    X           X                                    |          5 |
      Serosa, Histiocytic Sarcoma,         |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
      Serosa, Mesothelioma Malignant,      |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Histiocytic Sarcoma                  |                                        X                                 |          2 |
      Leukemia Mononuclear                 |    X           X  X     X     X  X  X                                    |         28 |
      Mesothelioma Malignant               |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  52                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                X           X                                             |             
      Colon, Serosa, Rectum, Mesothelioma  |                                                                          |             
          Malignant, Metastatic            |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                            X                                             |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  M  +  +     +  +  +     M     +  +  +     M        +  +               |             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +     +  +  +           +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |          X                                                               |             
      Ileum, Mesothelioma Malignant,       |                                                                          |             
          Metastatic                       |                                                                          |             
      Serosa, Mesothelioma Malignant,      |                                                                          |             
          Metastatic                       |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                            X                                             |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leiomyosarcoma                       |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +  +  +      |             
      Histiocytic Sarcoma, Metastatic      |                      X                                                   |             
      Leukemia Mononuclear                 |          X     X  X        X  X  X  X                 X     X  X         |             
      Mesothelioma Malignant               |                                                                          |             
      Mesothelioma Malignant, Metastatic   |                                                                          |             
      Neoplastic Nodule                    |                                                             X     X      |             
      Bile Duct, Leiomyosarcoma, Extension,|                                                                          |             
           Metastatic, Intestine Small     |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                +  +                 +              +                     |             
      Leiomyosarcoma, Extension,           |                                                                          |             
          Metastatic, Intestine Small      |                                                                          |             
      Leukemia Mononuclear                 |                X                                                         |             
      Mesothelioma Malignant               |                                                                          |             
      Mesothelioma Malignant, Metastatic   |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |          X     X           X                                             |             
      Mesothelioma Malignant, Metastatic   |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                X                                                         |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  53                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Serosa, Glandular, Mesothelioma      |                                                                          |             
          Malignant, Metastatic            |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                X           X                                             |             
                                            __________________________________________________________________________|             
   Tooth                                   |                +                 +  +                                    |             
      Pulp, Leukemia Mononuclear           |                X                 X  X                                    |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |          X     X  X        X     X  X                 X                  |             
      Atrium, Histiocytic Sarcoma,         |                                                                          |             
          Metastatic                       |                      X                                                   |             
      Atrium Right, Liposarcoma,           |                                                                          |             
          Metastatic, Skin                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +     +      |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |          X     X  X        X     X  X                                    |             
      Capsule, Mesothelioma Malignant,     |                                                                          |             
           Metastatic                      |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +     +      |             
      Leukemia Mononuclear                 |                X  X        X        X                                    |             
      Pheochromocytoma Malignant           | X                                                                 X      |             
      Pheochromocytoma Benign              |                X              X                       X     X            |             
      Bilateral, Pheochromocytoma Benign   |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +     +  +  +     +     +  +  +     +        +  +  M            |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X     X           X  X                       X     X            |             
      Pars Distalis, Adenoma               |                                                 X                        |             
      Pars Distalis, Carcinoma             |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                                                                          |             
      C-Cell, Adenoma                      |          X                                                               |             
      C-Cell, Carcinoma                    |                      X                                                   |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  54                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                                     X                                    |             
      Mesothelioma Malignant, Metastatic   |                                                                          |             
                                            __________________________________________________________________________|             
   Penis                                   |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +     +  +  +     M  +  +  +  +     M        +  +               |             
      Adenoma                              |          X                             X                                 |             
      Carcinoma                            |                                                                          |             
      Leukemia Mononuclear                 |                X                    X                 X                  |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +     +  +  +     +     +  +  +     +  +     +  +               |             
      Adenoma                              |                                                                          |             
      Leukemia Mononuclear                 |                   X              X                                       |             
      Serosa, Mesothelioma Malignant,      |                                                                          |             
          Metastatic                       |                                                                          |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                X                 X                                       |             
      Serosa, Mesothelioma Malignant,      |                                                                          |             
          Metastatic                       |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X                       X  X                       X  X         |             
      Bilateral, Interstitial Cell, Adenoma| X  X  X  X        X  X           X     X        X  X  X     X  X  X      |             
      Interstitial Cell, Adenoma           |                X              X     X                                    |             
      Tunic, Mesothelioma Malignant        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   | +        +     +  +        +  +  +  +  +              +     +            |             
      Leukemia Mononuclear                 |          X     X  X        X  X     X                 X     X            |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |          X     X  X        X     X  X                                    |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +     +  +  +     +  +  +  +  +     +        +  +               |             
      Bronchial, Leukemia Mononuclear      |                                                                          |             
      Deep Cervical, Leukemia Mononuclear  |                                                                          |             
      Iliac, Leukemia Mononuclear          |                                                                          |             
      Inguinal, Leukemia Mononuclear       |                                                                          |             
      Lumbar, Leukemia Mononuclear         |                               X  X                    X                  |             
      Mediastinal, Histiocytic Sarcoma,    |                                                                          |             
           Metastatic                      |                      X                                                   |             
      Mediastinal, Leukemia Mononuclear    |                                  X                                       |             
      Pancreatic, Leukemia Mononuclear     |                X                    X                                    |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +     +  M  +     +  +  +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |          X     X              X     X                 X                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +     +  +  +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |          X     X  X        X  X  X  X                 X                  |             
      Mesothelioma Malignant, Metastatic   |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +     +  +  +     +  +  +  +  +     +  +     +  +  +  +  +      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  55                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Leiomyosarcoma, Metastatic,          |                                                                          |             
          Intestine Small                  |                                                                          |             
      Leukemia Mononuclear                 |          X     X  X        X  X  X  X                 X     X  X         |             
      Capsule, Mesothelioma Malignant      |                                                                          |             
      Capsule, Mesothelioma Malignant,     |                                                                          |             
           Metastatic                      |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  +  +     +  +  +     +  M  +  +  +     +        +  M               |             
      Leukemia Mononuclear                 |          X     X  X        X     X  X                 X                  |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  M  +        +  +  +     +     +  +  +     M        +  M               |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +     +  +  +     +     +  +  +     +  +     +  +               |             
      Basosquamous Tumor Malignant         |                                                                          |             
      Subcutaneous Tissue, Fibroma         |                X                                                         |             
      Subcutaneous Tissue, Fibrosarcoma    |                                                 X                        |             
      Subcutaneous Tissue, Histiocytic     |                                                                          |             
          Sarcoma                          |                      X                                                   |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |                X                                      X                  |             
      Subcutaneous Tissue, Lipoma          |       X                                                                  |             
      Subcutaneous Tissue, Liposarcoma     |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         | +                    +                                                   |             
      Leiomyosarcoma, Metastatic,          |                                                                          |             
          Intestine Small                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                X           X                                             |             
      Meninges, Leukemia Mononuclear       |                                                                          |             
      Meninges, Cerebrum, Histiocytic      |                                                                          |             
          Sarcoma, Metastatic              |                      X                                                   |             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                      +                                                   |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                +           +     +     +     +           +               |             
      Leukemia Mononuclear                 |                            X                                             |             
      Meninges, Leukemia Mononuclear       |                X                 X                                       |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Carcinoma, Metastatic, Zymbal's Gland| X                                                                        |             
      Histiocytic Sarcoma, Metastatic      |                      X                                                   |             
      Leukemia Mononuclear                 |          X     X  X        X     X  X                 X                  |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  56                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Liposarcoma, Metastatic, Skin        |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                X                 X  X                                    |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                   +                                            +         |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                   +                                                      |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          | +                                                                        |             
      Adenoma                              |                                                                          |             
      Carcinoma                            | X                                                                        |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +  +  +      |             
      Leukemia Mononuclear                 |          X     X  X        X  X     X                 X     X  X         |             
      Capsule, Mesothelioma Malignant,     |                                                                          |             
           Metastatic                      |                                                                          |             
      Renal Tubule, Adenoma                |                   X                             X  X                     |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Leukemia Mononuclear                 |                X                                      X                  |             
      Serosa, Mesothelioma Malignant,      |                                                                          |             
          Metastatic                       |                                                                          |             
      Transitional Epithelium, Carcinoma,  |                                                                          |             
           Papillary                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +  +  +      |             
      Histiocytic Sarcoma                  |                      X                                                   |             
      Leukemia Mononuclear                 |          X     X  X        X  X  X  X                 X     X  X         |             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  57                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  A  A        +  +           +        +  +  +  +     +     +  A  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Colon, Serosa, Rectum, Mesothelioma  |                                                                          |             
          Malignant, Metastatic            |                                                    X                     |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  A        +  +           +        +  +     +     +     +  +  +|             
      Leukemia Mononuclear                 |    X                                                  X                  |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  M  +        +  +           +        +  +     +     +     +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X                                                                     |             
      Ileum, Mesothelioma Malignant,       |                                                                          |             
          Metastatic                       |                                                    X                     |             
      Serosa, Mesothelioma Malignant,      |                                                                          |             
          Metastatic                       |                                                             X            |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  A  A        +  +           +        +  +     +     +     +  A  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  A  A        +  +           +        +  A  +  +     +     +  A  +|             
      Leiomyosarcoma                       |                         X                                                |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |    X  X              X           X           X     X  X           X     X|             
      Mesothelioma Malignant               |                                                                          |             
      Mesothelioma Malignant, Metastatic   |                                                    X        X            |             
      Neoplastic Nodule                    |                                                                          |             
      Bile Duct, Leiomyosarcoma, Extension,|                                                                          |             
           Metastatic, Intestine Small     |                         X                                                |             
                                            __________________________________________________________________________|             
   Mesentery                               | +  +     +              +     +                 +  +        +     +     +|             
      Leiomyosarcoma, Extension,           |                                                                          |             
          Metastatic, Intestine Small      |                         X                                                |             
      Leukemia Mononuclear                 |    X                                                              X     X|             
      Mesothelioma Malignant               |                                                                          |             
      Mesothelioma Malignant, Metastatic   |                                                    X        X            |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |                                                                   X      |             
      Mesothelioma Malignant, Metastatic   |                                                    X        X            |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |                                                                   X      |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  58                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Serosa, Glandular, Mesothelioma      |                                                                          |             
          Malignant, Metastatic            |                                                    X        X            |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  A  +        +  +           +        +  +     +           +  +  +|             
      Leukemia Mononuclear                 |    X                                                  X                 X|             
                                            __________________________________________________________________________|             
   Tooth                                   |    +                                                  +           +     +|             
      Pulp, Leukemia Mononuclear           |    X                                                  X           X     X|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X  X                                               X           X     X|             
      Atrium, Histiocytic Sarcoma,         |                                                                          |             
          Metastatic                       |                                                                          |             
      Atrium Right, Liposarcoma,           |                                                                          |             
          Metastatic, Skin                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +  +     +  +  +     +     +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +           +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X                 X                                X           X     X|             
      Capsule, Mesothelioma Malignant,     |                                                                          |             
           Metastatic                      |                                                             X            |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +  M     +  +  +     +     +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X  X              X                                X           X     X|             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |       X                       X                    X  X           X  X  X|             
      Bilateral, Pheochromocytoma Benign   |                         X                                                |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
      Adenoma                              | X                                                                        |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +        +  +           +        +  +  +  +     M     +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                   X     X|             
      Pars Distalis, Adenoma               |             X           X                    X                           |             
      Pars Distalis, Carcinoma             |                                     X                                    |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +     +  +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |                                                                   X     X|             
      C-Cell, Adenoma                      |                   X                                                      |             
      C-Cell, Carcinoma                    |                      X                                                   |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                              +                           |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  59                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
      Mesothelioma Malignant, Metastatic   |                                                    X                     |             
                                            __________________________________________________________________________|             
   Penis                                   |                                                                   +      |             
      Leukemia Mononuclear                 |                                                                   X      |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  M  +  +     +  +  +           +        +  +  M  +     M     +  +  +|             
      Adenoma                              | X                 X     X                                         X     X|             
      Carcinoma                            |                      X                                                   |             
      Leukemia Mononuclear                 |    X                                                              X      |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +           +        +  +  +  +     +     +  +  +|             
      Adenoma                              |                                                                   X      |             
      Leukemia Mononuclear                 |                                                                   X     X|             
      Serosa, Mesothelioma Malignant,      |                                                                          |             
          Metastatic                       |                                                             X            |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +        +  +           +        +  +  M  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X                                                              X     X|             
      Serosa, Mesothelioma Malignant,      |                                                                          |             
          Metastatic                       |                                                             X            |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                    X  X           X     X|             
      Bilateral, Interstitial Cell, Adenoma| X  X           X  X  X        X  X              X  X  X        X     X   |             
      Interstitial Cell, Adenoma           |          X  X           X           X        X              X     X     X|             
      Tunic, Mesothelioma Malignant        |                                                    X        X            |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |    +  +              +                       +     +  +     +     +     +|             
      Leukemia Mononuclear                 |    X  X              X                             X  X           X     X|             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X                 X                             X  X           X     X|             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +  +        +  +           +        +  +  +  +     +  +  +  +  +|             
      Bronchial, Leukemia Mononuclear      |                                                    X                     |             
      Deep Cervical, Leukemia Mononuclear  |    X                                                                     |             
      Iliac, Leukemia Mononuclear          |                      X                                                   |             
      Inguinal, Leukemia Mononuclear       |                                                                         X|             
      Lumbar, Leukemia Mononuclear         |                      X                                                   |             
      Mediastinal, Histiocytic Sarcoma,    |                                                                          |             
           Metastatic                      |                                                                          |             
      Mediastinal, Leukemia Mononuclear    |                      X                                            X     X|             
      Pancreatic, Leukemia Mononuclear     |    X                                                                     |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X                 X                                X           X     X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +        +  +           +        +  +  +        +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                 X                                            X     X|             
      Mesothelioma Malignant, Metastatic   |                                                    X        X            |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  A  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  60                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Leiomyosarcoma, Metastatic,          |                                                                          |             
          Intestine Small                  |                         X                                                |             
      Leukemia Mononuclear                 |    X  X              X           X           X     X  X           X     X|             
      Capsule, Mesothelioma Malignant      |                                                                          |             
      Capsule, Mesothelioma Malignant,     |                                                                          |             
           Metastatic                      |                                                    X        X            |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  M  +        +  +     +     +        +  +  M  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X                 X                                X           X     X|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  M  M  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  M  +        +  +           +        +  +  +  +     +     +  +  +|             
      Basosquamous Tumor Malignant         |                                                                          |             
      Subcutaneous Tissue, Fibroma         |                                                                          |             
      Subcutaneous Tissue, Fibrosarcoma    |                                                                          |             
      Subcutaneous Tissue, Histiocytic     |                                                                          |             
          Sarcoma                          |                                                                          |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |                                                                   X      |             
      Subcutaneous Tissue, Lipoma          |                                                                          |             
      Subcutaneous Tissue, Liposarcoma     |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                         +                                                |             
      Leiomyosarcoma, Metastatic,          |                                                                          |             
          Intestine Small                  |                         X                                                |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X                                                                    X|             
      Meninges, Leukemia Mononuclear       |                                                                   X      |             
      Meninges, Cerebrum, Histiocytic      |                                                                          |             
          Sarcoma, Metastatic              |                                                                          |             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |       +     +                                      +        +            |             
      Leukemia Mononuclear                 |                                                                          |             
      Meninges, Leukemia Mononuclear       |                                                    X                     |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Carcinoma, Metastatic, Zymbal's Gland|                                                                          |             
      Histiocytic Sarcoma, Metastatic      |                                                                          |             
      Leukemia Mononuclear                 |    X  X              X                             X  X           X     X|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  61                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Liposarcoma, Metastatic, Skin        |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X                 X                             X  X           X     X|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                              +        +                  |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                 +                        |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                 +                        |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                   +                          +        +                  |             
      Adenoma                              |                                              X                           |             
      Carcinoma                            |                   X                                   X                  |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X              X                             X  X           X     X|             
      Capsule, Mesothelioma Malignant,     |                                                                          |             
           Metastatic                      |                                                             X            |             
      Renal Tubule, Adenoma                |                                                             X            |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Leukemia Mononuclear                 |    X                                                              X      |             
      Serosa, Mesothelioma Malignant,      |                                                                          |             
          Metastatic                       |                                                    X        X            |             
      Transitional Epithelium, Carcinoma,  |                                                                          |             
           Papillary                       |             X                                                            |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |    X  X              X           X           X     X  X           X     X|             
      Mesothelioma Malignant               |                                                    X        X            |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  62                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |     A      |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +        +           +  +        +  +                                 |  37        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         | +  +        +           +  +        +  +                                 |  37        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +        +           +  +        +  +                                 |  34        |
      Leukemia Mononuclear                 |                                                                          |          2 |
      Colon, Serosa, Rectum, Mesothelioma  |                                                                          |            |
          Malignant, Metastatic            |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +        +           +  +        +  +                                 |  35        |
      Leukemia Mononuclear                 |                         X                                                |          4 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +        +           +  +        +  +                                 |  32        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small                         | +  +        +           +  +        +  +                                 |  36        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +        +           +  +        +  +                                 |  35        |
      Leukemia Mononuclear                 |                                                                          |          2 |
      Ileum, Mesothelioma Malignant,       |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
      Serosa, Mesothelioma Malignant,      |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +        +           +  +        +  +                                 |  33        |
      Leukemia Mononuclear                 |                                     X                                    |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | M  M        +           +  +        +  +                                 |  30        |
      Leiomyosarcoma                       |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Histiocytic Sarcoma, Metastatic      |                                                                          |          1 |
      Leukemia Mononuclear                 |          X  X           X  X  X  X  X                                    |         26 |
      Mesothelioma Malignant               |                   X                                                      |          1 |
      Mesothelioma Malignant, Metastatic   |                                                                          |          2 |
      Neoplastic Nodule                    |                                                                          |          2 |
      Bile Duct, Leiomyosarcoma, Extension,|                                                                          |            |
           Metastatic, Intestine Small     |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                   +                    +                                 |  16        |
      Leiomyosarcoma, Extension,           |                                                                          |            |
          Metastatic, Intestine Small      |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          4 |
      Mesothelioma Malignant               |                   X                                                      |          1 |
      Mesothelioma Malignant, Metastatic   |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +        +           +  +        +  +                                 |  36        |
      Leukemia Mononuclear                 |                                                                          |          4 |
      Mesothelioma Malignant, Metastatic   |                                                                          |          2 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  63                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |     A      |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +        +           +  +        +  +                                 |  37        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach                                 | +  +        +           +  +        +  +                                 |  36        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +        +           +  +        +  +                                 |  36        |
      Leukemia Mononuclear                 |                                     X                                    |          2 |
      Serosa, Glandular, Mesothelioma      |                                                                          |            |
          Malignant, Metastatic            |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +        +           +  +        +  +                                 |  34        |
      Leukemia Mononuclear                 |                                                                          |          5 |
                                            __________________________________________________________________________|____________|
   Tooth                                   |             +           +                                                |   9        |
      Pulp, Leukemia Mononuclear           |             X           X                                                |          9 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +        +           +  +  +     +  +                                 |  38        |
      Leukemia Mononuclear                 |             X           X  X  X     X                                    |         17 |
      Atrium, Histiocytic Sarcoma,         |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
      Atrium Right, Liposarcoma,           |                                                                          |            |
          Metastatic, Skin                 | X                                                                        |          1 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +  +  +  +  +     +  +  +     +  +                                 |  49        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +                 +  +  +     +  +                                 |  37        |
      Leukemia Mononuclear                 |                         X  X  X                                          |         14 |
      Capsule, Mesothelioma Malignant,     |                                                                          |            |
           Metastatic                      |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +  +  +  +  +     +  +  +     +  +                                 |  48        |
      Leukemia Mononuclear                 |                         X  X  X                                          |         13 |
      Pheochromocytoma Malignant           |                                                                          |          2 |
      Pheochromocytoma Benign              |                X  X                 X                                    |         14 |
      Bilateral, Pheochromocytoma Benign   |       X                    X                                             |          3 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +        +           +  +        +  +                                 |  36        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +        +           +  +        +  +                                 |  36        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  M  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |             X                                                            |          9 |
      Pars Distalis, Adenoma               |                X        X        X  X  X                                 |          9 |
      Pars Distalis, Carcinoma             |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +        +           +  +        +  +                                 |  38        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  64                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |     A      |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |                                     X                                    |          3 |
      C-Cell, Adenoma                      |                                                                          |          2 |
      C-Cell, Carcinoma                    |                                                                          |          2 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Coagulating Gland                       |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +        +           +  +        +  +                                 |  37        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Mesothelioma Malignant, Metastatic   |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Penis                                   |                                                                          |   1        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | M  +        +  +        +  +        +  +                                 |  34        |
      Adenoma                              |                X                                                         |          8 |
      Carcinoma                            |                                                                          |          1 |
      Leukemia Mononuclear                 |                         X           X                                    |          7 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +        +           +  +  +     +  +                                 |  41        |
      Adenoma                              |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          4 |
      Serosa, Mesothelioma Malignant,      |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +        +           +  +        +  +                                 |  36        |
      Leukemia Mononuclear                 |                                     X                                    |          6 |
      Serosa, Mesothelioma Malignant,      |                                                                          |            |
          Metastatic                       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +     +  +  +  +  +  +  +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |                                                                          |          9 |
      Bilateral, Interstitial Cell, Adenoma|       X     X  X  X  X  X  X  X  X     X                                 |         36 |
      Interstitial Cell, Adenoma           |    X                                X                                    |         13 |
      Tunic, Mesothelioma Malignant        |                   X                                                      |          3 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |             +           +  +  +     +                                    |  25        |
      Leukemia Mononuclear                 |             X           X  X  X     X                                    |         20 |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +        +           +  +        +  +                                 |  37        |
      Leukemia Mononuclear                 |             X                       X                                    |         14 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +     +           +  +  +     +  +                                 |  41        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  65                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |     A      |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Bronchial, Leukemia Mononuclear      |                                                                          |          1 |
      Deep Cervical, Leukemia Mononuclear  |                                                                          |          1 |
      Iliac, Leukemia Mononuclear          |                                                                          |          1 |
      Inguinal, Leukemia Mononuclear       |                                                                          |          1 |
      Lumbar, Leukemia Mononuclear         |                                                                          |          4 |
      Mediastinal, Histiocytic Sarcoma,    |                                                                          |            |
           Metastatic                      |                                                                          |          1 |
      Mediastinal, Leukemia Mononuclear    |                         X  X        X                                    |          7 |
      Pancreatic, Leukemia Mononuclear     |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +        +           +  +  +     +  +                                 |  38        |
      Leukemia Mononuclear                 |                         X  X  X     X                                    |         14 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +        +           +  +        +  +                                 |  38        |
      Leukemia Mononuclear                 |             X           X           X                                    |         15 |
      Mesothelioma Malignant, Metastatic   |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +     +  +  +  +  +  +  +  +  +  +  +                                 |  52        |
      Leiomyosarcoma, Metastatic,          |                                                                          |            |
          Intestine Small                  |                                                                          |          1 |
      Leukemia Mononuclear                 |          X  X           X  X  X  X  X                                    |         26 |
      Capsule, Mesothelioma Malignant      |                   X                                                      |          1 |
      Capsule, Mesothelioma Malignant,     |                                                                          |            |
           Metastatic                      |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M     +  M  M     +  +  +  M  +  +                                 |  35        |
      Leukemia Mononuclear                 |                         X     X     X                                    |         15 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M        +           +  +        +  +                                 |  29        |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +        +           +  +        +  +                                 |  37        |
      Basosquamous Tumor Malignant         |                         X                                                |          1 |
      Subcutaneous Tissue, Fibroma         |                                                                          |          1 |
      Subcutaneous Tissue, Fibrosarcoma    |                                                                          |          1 |
      Subcutaneous Tissue, Histiocytic     |                                                                          |            |
          Sarcoma                          |                                                                          |          1 |
      Subcutaneous Tissue, Leukemia        |                                                                          |            |
          Mononuclear                      |                         X                                                |          4 |
      Subcutaneous Tissue, Lipoma          |                                                                          |          1 |
      Subcutaneous Tissue, Liposarcoma     | X                                                                        |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +        +           +  +        +  +                                 |  37        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  66                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |     A      |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   3        |
      Leiomyosarcoma, Metastatic,          |                                                                          |            |
          Intestine Small                  |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +        +           +  +        +  +                                 |  37        |
      Leukemia Mononuclear                 |                            X                                             |          5 |
      Meninges, Leukemia Mononuclear       |                                                                          |          1 |
      Meninges, Cerebrum, Histiocytic      |                                                                          |            |
          Sarcoma, Metastatic              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             | +  +                    +                                                |  13        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Meninges, Leukemia Mononuclear       |                         X                                                |          4 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +     +           +  +        +  +                                 |  38        |
      Carcinoma, Metastatic, Zymbal's Gland|                                                                          |          1 |
      Histiocytic Sarcoma, Metastatic      |                                                                          |          1 |
      Leukemia Mononuclear                 |             X           X  X                                             |         17 |
      Liposarcoma, Metastatic, Skin        | X                                                                        |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +        +           +  +        +  +                                 |  37        |
      Leukemia Mononuclear                 |                         X  X                                             |         11 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +        +           +  +        +  +                                 |  37        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |                                                                          |   2        |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   3        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   2        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                          |   4        |
      Adenoma                              |                                                                          |          1 |
      Carcinoma                            |                                                                          |          3 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |          X  X           X     X  X  X                                    |         22 |
      Capsule, Mesothelioma Malignant,     |                                                                          |            |
           Metastatic                      |                                                                          |          1 |
      Renal Tubule, Adenoma                |                                                                          |          4 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  67                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |     A      |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 URINARY SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +        +           +  +        +  +                                 |  37        |
      Leukemia Mononuclear                 |                                                                          |          4 |
      Serosa, Mesothelioma Malignant,      |                                                                          |            |
          Metastatic                       |                                                                          |          2 |
      Transitional Epithelium, Carcinoma,  |                                                                          |            |
           Papillary                       |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |          X  X           X  X  X  X  X                                    |         26 |
      Mesothelioma Malignant               |                   X                                                      |          3 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  68                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 6| 6| 6| 6| 5| 7| 7| 6| 6| 4| 7| 6| 6| 5| 5| 7| 7| 7| 7| 6|             
                             DAY ON TEST   | 1| 7| 5| 5| 1| 8| 8| 7| 3| 2| 3| 2| 1| 0| 5| 0| 8| 1| 6| 5| 3| 3| 3| 0| 4|             
                                           | 8| 2| 9| 9| 8| 9| 6| 2| 1| 2| 1| 0| 2| 6| 9| 0| 2| 2| 2| 4| 2| 1| 1| 7| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +        +  +  +  +  +  +  +  A  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +           +  +  +  +  +  +  +  A  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +        +  +  +  +  +  +  +  A  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +           M  +  +  +  +  +  +  A  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +           +  +  +  +  +  +  +  A  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                X         |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +           +  +  +  +  +  +  +  A  +  +     +  M  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Hepatocellular Adenoma               |                                                                          |             
      Histiocytic Sarcoma                  |                                                          X               |             
      Leukemia Mononuclear                 |                   X  X     X  X     X  X           X  X  X     X        X|             
      Neoplastic Nodule                    |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                            +           +                 +     +         |             
      Leukemia Mononuclear                 |                            X           X                 X     X         |             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                          X     X         |             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                          X     X         |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |                   +                                      +     +         |             
      Pulp, Leukemia Mononuclear           |                                                          X     X         |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X  X                 X           X  X  X     X         |             
      Schwannoma NOS                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X  X        X        X           X  X        X        X|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X  X     X           X           X  X  X     X        X|             
      Pheochromocytoma Malignant           |                                                             X            |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  69                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 6| 6| 6| 6| 5| 7| 7| 6| 6| 4| 7| 6| 6| 5| 5| 7| 7| 7| 7| 6|             
                             DAY ON TEST   | 1| 7| 5| 5| 1| 8| 8| 7| 3| 2| 3| 2| 1| 0| 5| 0| 8| 1| 6| 5| 3| 3| 3| 0| 4|             
                                           | 8| 2| 9| 9| 8| 9| 6| 2| 1| 2| 1| 0| 2| 6| 9| 0| 2| 2| 2| 4| 2| 1| 1| 7| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Pheochromocytoma Benign              |    X                                X                       X     X      |             
      Bilateral, Pheochromocytoma Benign   |                                  X                             X         |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  M  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                          X               |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +        +  +  +  +  M  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X                             X  X  X     X         |             
      Pars Distalis, Adenoma               |                   X                                                      |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                X         |             
      C-Cell, Adenoma                      |                                                 X                        |             
      C-Cell, Carcinoma                    |                                                                   X      |             
      Follicular Cell, Adenoma             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                        +                                 |             
      Leukemia Mononuclear                 |                                        X                                 |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                        X                 X               |             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +        M  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                      X        X                                          |             
      Carcinoma                            |                                                                          |             
      Leukemia Mononuclear                 |                                                          X     X         |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                          X               |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                        X              X  X               |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X                                X        X         |             
      Bilateral, Interstitial Cell, Adenoma| X  X           X  X  X  X     X  X     X     X  X     X  X  X  X  X  X  X|             
      Interstitial Cell, Adenoma           |                            X        X              X                     |             
      Tunic, Mesothelioma Malignant        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                   +  +     +        +  +           +  +  +     +  +      |             
      Leukemia Mononuclear                 |                   X  X     X        X  X           X  X  X     X         |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X  X                 X           X  X  X     X         |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Inguinal, Leukemia Mononuclear       |                                                          X               |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  70                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 6| 6| 6| 6| 5| 7| 7| 6| 6| 4| 7| 6| 6| 5| 5| 7| 7| 7| 7| 6|             
                             DAY ON TEST   | 1| 7| 5| 5| 1| 8| 8| 7| 3| 2| 3| 2| 1| 0| 5| 0| 8| 1| 6| 5| 3| 3| 3| 0| 4|             
                                           | 8| 2| 9| 9| 8| 9| 6| 2| 1| 2| 1| 0| 2| 6| 9| 0| 2| 2| 2| 4| 2| 1| 1| 7| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Lumbar, Leukemia Mononuclear         |                                                                          |             
      Mediastinal, Leukemia Mononuclear    |                                        X           X           X         |             
      Pancreatic, Leukemia Mononuclear     |                                     X  X           X           X         |             
      Renal, Leukemia Mononuclear          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X  X     X        X  X           X  X  X     X         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X     X        X  X           X  X  X     X         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X  X     X  X     X  X           X  X  X     X        X|             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X     X           X              X  X     X         |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +        +  +  +  +  +  +  +  +  +  +     M  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +        +  +  +  +  +  +  +  +  +  +     M  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   | X                             X                                          |             
      Keratoacanthoma                      |                                        X                                 |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |                                                          X               |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Rib, Osteosarcoma                    |                                                                          |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                         +                                +               |             
      Leukemia Mononuclear                 |                                                          X               |             
      Osteosarcoma, Extension, Metastatic, |                                                                          |             
           Bone                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                        X                 X               |             
      Meninges, Leukemia Mononuclear       |                            X                          X  X               |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                          +               |             
      Meninges, Leukemia Mononuclear       |                                                          X               |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  |                                                 +                        |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                          X               |             
      Leukemia Mononuclear                 |                   X  X     X        X  X           X  X  X     X         |             
      Osteosarcoma, Metastatic, Bone       |                                                                          |             
      Pheochromocytoma Malignant,          |                                                                          |             
          Metastatic, Adrenal Gland        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  71                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 6| 6| 6| 6| 5| 7| 7| 6| 6| 4| 7| 6| 6| 5| 5| 7| 7| 7| 7| 6|             
                             DAY ON TEST   | 1| 7| 5| 5| 1| 8| 8| 7| 3| 2| 3| 2| 1| 0| 5| 0| 8| 1| 6| 5| 3| 3| 3| 0| 4|             
                                           | 8| 2| 9| 9| 8| 9| 6| 2| 1| 2| 1| 0| 2| 6| 9| 0| 2| 2| 2| 4| 2| 1| 1| 7| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X                                X  X     X         |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                               +     +                                    |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                  +                                       |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
      Carcinoma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                          X               |             
      Leukemia Mononuclear                 |                   X  X     X        X  X           X  X  X     X        X|             
      Renal Tubule, Adenoma                | X                 X                                         X  X         |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                    X              X                  |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                          X               |             
      Leukemia Mononuclear                 |                   X  X     X  X     X  X           X  X  X     X        X|             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  72                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 5| 5| 4| 7| 7| 7| 6| 5|             
                             DAY ON TEST   | 3| 3| 6| 5| 5| 3| 3| 3| 3| 5| 3| 1| 0| 3| 0| 3| 1| 9| 8| 5| 3| 3| 3| 5| 0|             
                                           | 2| 1| 9| 9| 9| 2| 2| 2| 2| 9| 1| 0| 0| 7| 6| 1| 1| 7| 1| 9| 1| 1| 1| 9| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +        +  +  +  +     +  A  +  +  A  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +        +  +  +  +     +  +  +  +  A  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                                                      |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +        +  +  +  +     +  +     +  A  +  +  A  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +        +  +  +  +     +  A  +  +  A  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Hepatocellular Adenoma               |                               X                                          |             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 | X  X  X           X  X  X              X        X  X  X     X  X     X   |             
      Neoplastic Nodule                    |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               | +                 +                 +                                   +|             
      Leukemia Mononuclear                 |                   X                                                      |             
      Mesothelioma Malignant               | X                                                                        |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                                         X        X   |             
      Mesothelioma Malignant               | X                                                                        |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                                                  X   |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Mesothelioma Malignant               | X                                                                        |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                             X            |             
                                            __________________________________________________________________________|             
   Tooth                                   | +                 +  +  +                             +     +            |             
      Pulp, Leukemia Mononuclear           | X                 X  X                                X     X            |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X  X           X  X  X                       X     X              X   |             
      Schwannoma NOS                       |                                              X                           |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 | X     X           X  X  X                          X  X              X   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 | X     X           X  X                          X  X  X              X   |             
      Pheochromocytoma Malignant           |                         X                                                |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  73                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 5| 5| 4| 7| 7| 7| 6| 5|             
                             DAY ON TEST   | 3| 3| 6| 5| 5| 3| 3| 3| 3| 5| 3| 1| 0| 3| 0| 3| 1| 9| 8| 5| 3| 3| 3| 5| 0|             
                                           | 2| 1| 9| 9| 9| 2| 2| 2| 2| 9| 1| 0| 0| 7| 6| 1| 1| 7| 1| 9| 1| 1| 1| 9| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Pheochromocytoma Benign              |    X  X           X                             X              X  X      |             
      Bilateral, Pheochromocytoma Benign   |                                                                      X   |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +        +  +  M  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X                                X              X   |             
      Pars Distalis, Adenoma               |                                  X                                       |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                                                     |             
      C-Cell, Adenoma                      |                               X                       X                  |             
      C-Cell, Carcinoma                    |                      X              X                                    |             
      Follicular Cell, Adenoma             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                                                   +      |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                             X            |             
      Mesothelioma Malignant               | X                                                                        |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Adenoma                              |    X                          X           X                              |             
      Carcinoma                            |                                                                         X|             
      Leukemia Mononuclear                 |                   X                    X        X           X        X   |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                             X                    X   |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                             X                    X   |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                                         X        X   |             
      Bilateral, Interstitial Cell, Adenoma| X  X  X        X  X  X  X     X  X  X  X  X  X  X  X  X     X  X  X  X   |             
      Interstitial Cell, Adenoma           |                                                                          |             
      Tunic, Mesothelioma Malignant        | X                                                                        |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   | +  +  +           +  +  +     +        +     +  +  +        +  +     +  +|             
      Leukemia Mononuclear                 | X  X  X           X  X                 X        X  X                 X   |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X              X                    X        X  X  X              X   |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Inguinal, Leukemia Mononuclear       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  74                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 5| 5| 4| 7| 7| 7| 6| 5|             
                             DAY ON TEST   | 3| 3| 6| 5| 5| 3| 3| 3| 3| 5| 3| 1| 0| 3| 0| 3| 1| 9| 8| 5| 3| 3| 3| 5| 0|             
                                           | 2| 1| 9| 9| 9| 2| 2| 2| 2| 9| 1| 0| 0| 7| 6| 1| 1| 7| 1| 9| 1| 1| 1| 9| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Lumbar, Leukemia Mononuclear         |                         X                                      X         |             
      Mediastinal, Leukemia Mononuclear    | X  X              X                                X                     |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
      Renal, Leukemia Mononuclear          |                   X                                                      |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +        +  +  +  +     +  +  +  +  +     +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |    X              X                             X  X  X                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +        +  +  +  +     +  +  +  +  +     +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X              X  X  X                       X  X  X              X   |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X  X           X  X  X              X        X  X  X     X  X  X  X   |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  M  +        M  +  M  M     +  +  M  +  +  +  +  M  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                                   X              X   |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +        +  +  +  +     +  +  +  +  +  +  +  M  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                                          |             
      Keratoacanthoma                      |                                                                          |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      |                   X                                                      |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Rib, Osteosarcoma                    |                                           X                              |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |       +                                   +                       +      |             
      Leukemia Mononuclear                 |       X                                                                  |             
      Osteosarcoma, Extension, Metastatic, |                                                                          |             
           Bone                            |                                           X                              |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                       X                  |             
      Meninges, Leukemia Mononuclear       |                      X                                               X   |             
                                            __________________________________________________________________________|             
   Spinal Cord                             | +                    +  +              +                    +           +|             
      Meninges, Leukemia Mononuclear       | X                    X  X              X                    X            |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 | X  X  X           X  X  X              X        X  X  X     X  X     X   |             
      Osteosarcoma, Metastatic, Bone       |                                           X                              |             
      Pheochromocytoma Malignant,          |                                                                          |             
          Metastatic, Adrenal Gland        |                         X                                                |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  75                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 5| 5| 4| 7| 7| 7| 6| 5|             
                             DAY ON TEST   | 3| 3| 6| 5| 5| 3| 3| 3| 3| 5| 3| 1| 0| 3| 0| 3| 1| 9| 8| 5| 3| 3| 3| 5| 0|             
                                           | 2| 1| 9| 9| 9| 2| 2| 2| 2| 9| 1| 0| 0| 7| 6| 1| 1| 7| 1| 9| 1| 1| 1| 9| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X           X                                X  X              X   |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                  +              +                        |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
      Carcinoma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |    X  X           X  X                 X        X  X  X     X  X     X   |             
      Renal Tubule, Adenoma                |                         X                                         X      |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                             X                    X   |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 | X  X  X           X  X  X              X        X  X  X     X  X  X  X   |             
      Mesothelioma Malignant               | X                                                                        |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  76                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |     A      |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +     +  +  +  +     +  +  A  +                                 |  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +     +  +  +  +     +  +  +  +                                 |  52        |
                                            __________________________________________________________________________|____________|
   Intestine Small                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +     +  +  +  +     +  +  A  +                                 |  49        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +     +  A  +  +     +  +  A  +                                 |  48        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Hepatocellular Adenoma               |                                                                          |          1 |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 | X  X           X     X              X  X                                 |         30 |
      Neoplastic Nodule                    |                                  X                                       |          1 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |    +                                                                     |   9        |
      Leukemia Mononuclear                 |    X                                                                     |          6 |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +     +  +     +     +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |                                                                          |          5 |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 | X                                                                        |          5 |
                                            __________________________________________________________________________|____________|
   Stomach                                 | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                      +                                                   |  10        |
      Pulp, Leukemia Mononuclear           |                      X                                                   |          8 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 | X  X                                X  X                                 |         20 |
      Schwannoma NOS                       |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  77                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |     A      |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +  +     +  +     +     +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 | X  X                                   X                                 |         19 |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                        X                                 |         18 |
      Pheochromocytoma Malignant           |                   X                                                      |          3 |
      Pheochromocytoma Benign              |    X                    X        X                                       |         13 |
      Bilateral, Pheochromocytoma Benign   | X              X     X                                                   |          6 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 |                                                                          |          8 |
      Pars Distalis, Adenoma               |                X        X        X                                       |          5 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 | X                                                                        |          3 |
      C-Cell, Adenoma                      |                                                                          |          3 |
      C-Cell, Carcinoma                    |                                                                          |          3 |
      Follicular Cell, Adenoma             |                   X                                                      |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Coagulating Gland                       |                                                                          |   2        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          3 |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Adenoma                              | X                 X                                                      |          7 |
      Carcinoma                            |    X                                   X                                 |          3 |
      Leukemia Mononuclear                 |                                                                          |          7 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                     X                                    |          5 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          6 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          6 |
      Bilateral, Interstitial Cell, Adenoma| X  X  X        X              X                                          |         43 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  78                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |     A      |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Interstitial Cell, Adenoma           |                   X                 X  X                                 |          6 |
      Tunic, Mesothelioma Malignant        |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   | +  +                                +  +                                 |  29        |
      Leukemia Mononuclear                 | X                                   X  X                                 |         21 |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 | X                                   X  X                                 |         18 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Inguinal, Leukemia Mononuclear       |                                                                          |          1 |
      Lumbar, Leukemia Mononuclear         |                                                                          |          2 |
      Mediastinal, Leukemia Mononuclear    | X  X                                                                     |          9 |
      Pancreatic, Leukemia Mononuclear     |                                                                          |          4 |
      Renal, Leukemia Mononuclear          |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 | X                                   X                                    |         16 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Leukemia Mononuclear                 | X                                   X  X                                 |         20 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 | X  X           X     X              X  X                                 |         31 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +     +  +  +  +     +  M  +  M                                 |  46        |
      Leukemia Mononuclear                 |                                     X                                    |         10 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Basal Cell Adenoma                   |                                                                          |          2 |
      Keratoacanthoma                      |                               X                                          |          2 |
      Subcutaneous Tissue, Leukemia        |                                                                          |            |
          Mononuclear                      |                                                                          |          2 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Rib, Osteosarcoma                    |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                      +                                                   |   6        |
      Leukemia Mononuclear                 |                                                                          |          2 |
      Osteosarcoma, Extension, Metastatic, |                                                                          |            |
           Bone                            |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  79                                                               
NTP Experiment-Test: 05040-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 08:40:29  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |     T      |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |     A      |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |     L      |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 NERVOUS SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          3 |
      Meninges, Leukemia Mononuclear       |                                                                          |          5 |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |          +                          +                                    |   9        |
      Meninges, Leukemia Mononuclear       |                                     X                                    |          7 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 | X  X                                X  X                                 |         26 |
      Osteosarcoma, Metastatic, Bone       |                                                                          |          1 |
      Pheochromocytoma Malignant,          |                                                                          |            |
          Metastatic, Adrenal Gland        |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                     X  X                                 |         12 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                      +                 +                                 |   4        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   3        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |          +                                                               |   1        |
      Carcinoma                            |          X                                                               |          1 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 | X  X                                X  X                                 |         25 |
      Renal Tubule, Adenoma                |    X                    X                                                |          8 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Leukemia Mononuclear                 |                                                                          |          6 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 | X  X           X     X              X  X                                 |         31 |
      Mesothelioma Malignant               |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  80                                                               
                                  ------------------------------------------------------------                                      
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NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.