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TDMS Study 60968-01 Pathology Tables

NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52

                                                           CORE STUDY




       Facility:  Battelle Northwest

       Chemical CAS #:  0078-84-2

       Lock Date:  06/01/94

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All


































a  Number of animals examined microscopically at site and number of animals with lesion

                                                              Page   1

NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                17           22           22           13                                     
    Natural Death                                      6            3            4            5                                     
    Accidently Killed                                               1                                                               
  Survivors                                                                                                                         
    Terminal Sacrifice                                27           24           24           31                                     
    Natural Death                                                                             1                                     
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (49)         (50)         (50)         (50)                                   
   Intestine Small, Duodenum                          (48)         (47)         (49)         (47)                                   
   Intestine Small, Jejunum                           (47)         (47)         (49)         (45)                                   
      Carcinoma                                        1 (2%)                                                                       
   Intestine Small, Ileum                             (47)         (47)         (49)         (45)                                   
   Liver                                              (49)         (50)         (50)         (50)                                   
      Fibrous Histiocytoma, Metastatic, Skin                        1 (2%)                                                          
      Hepatocellular Adenoma                                        1 (2%)       2 (4%)                                             
   Mesentery                                          (7)          (7)          (8)          (4)                                    
      Fibrosarcoma                                     1 (14%)                                                                      
      Sarcoma                                                       1 (14%)                                                         
   Oral Mucosa                                        (4)                       (2)          (3)                                    
      Pharyngeal, Squamous Cell Carcinoma                                                     1 (33%)                               
   Pancreas                                           (49)         (49)         (49)         (50)                                   
   Stomach, Forestomach                               (49)         (49)         (50)         (50)                                   
   Stomach, Glandular                                 (48)         (49)         (50)         (50)                                   
   Tongue                                             (1)                       (1)          (2)                                    
      Squamous Cell Papilloma                          1 (100%)                  1 (100%)     1 (50%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (49)         (49)         (50)         (50)                                   
      Adenoma                                          1 (2%)                    1 (2%)       2 (4%)                                
      Fibrous Histiocytoma, Metastatic, Skin                        1 (2%)                                                          
   Adrenal Medulla                                    (49)         (49)         (47)         (49)                                   
                                                             Page   2                                                               
NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - cont                                                                                                             
      Pheochromocytoma Malignant                                                              1 (2%)                                
      Pheochromocytoma Benign                          1 (2%)                    2 (4%)                                             
   Islets, Pancreatic                                 (50)         (48)         (49)         (50)                                   
      Adenoma                                          2 (4%)       1 (2%)                    1 (2%)                                
      Carcinoma                                                                               1 (2%)                                
   Pituitary Gland                                    (48)         (50)         (49)         (50)                                   
      Carcinoma                                                     1 (2%)                                                          
      Pars Distalis, Adenoma                          34 (71%)     28 (56%)     33 (67%)     29 (58%)                               
   Thyroid Gland                                      (49)         (49)         (50)         (50)                                   
      C-Cell, Adenoma                                  1 (2%)       4 (8%)       2 (4%)       3 (6%)                                
      C-Cell, Carcinoma                                1 (2%)                                                                       
      Follicular Cell, Adenoma                                                   1 (2%)                                             
      Follicular Cell, Carcinoma                       1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (48)         (50)         (50)         (48)                                   
      Adenoma                                          1 (2%)       2 (4%)                    1 (2%)                                
      Carcinoma                                        4 (8%)       5 (10%)      4 (8%)       3 (6%)                                
   Ovary                                              (49)         (50)         (50)         (50)                                   
      Granulosa-Theca Tumor Malignant                               1 (2%)       1 (2%)                                             
      Bilateral, Fibrous Histiocytoma, Metastatic,                                                                                  
           Skin                                                     1 (2%)                                                          
   Uterus                                             (48)         (50)         (50)         (50)                                   
      Leiomyoma                                                                               1 (2%)                                
      Leiomyosarcoma                                                1 (2%)                                                          
      Polyp Stromal                                    2 (4%)       5 (10%)      1 (2%)       6 (12%)                               
      Sarcoma Stromal                                               2 (4%)                    1 (2%)                                
   Vagina                                                                                    (1)                                    
      Polyp                                                                                   1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (49)         (49)         (50)         (50)                                   
      Fibrous Histiocytoma, Metastatic, Skin                        1 (2%)                                                          
   Lymph Node                                         (4)          (4)          (4)          (5)                                    
      Fibrous Histiocytoma, Metastatic, Skin                        1 (25%)                                                         
   Lymph Node, Bronchial                              (49)         (50)         (50)         (50)                                   
      Fibrous Histiocytoma, Metastatic, Skin                        1 (2%)                                                          
   Lymph Node, Mandibular                             (45)         (50)         (46)         (46)                                   
                                                             Page   3                                                               
NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
      Fibrous Histiocytoma, Metastatic, Skin                        1 (2%)                                                          
   Lymph Node, Mesenteric                             (49)         (50)         (50)         (50)                                   
   Lymph Node, Mediastinal                            (48)         (49)         (50)         (50)                                   
      Fibrous Histiocytoma, Metastatic, Skin                        1 (2%)                                                          
   Spleen                                             (49)         (49)         (49)         (50)                                   
      Hemangiosarcoma                                  1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (50)         (50)         (50)                                   
      Carcinoma                                        1 (2%)       1 (2%)       5 (10%)      1 (2%)                                
      Carcinoma, Multiple                                                        1 (2%)                                             
      Fibroadenoma                                    23 (46%)     17 (34%)     19 (38%)     17 (34%)                               
      Fibroadenoma, Multiple                           4 (8%)       4 (8%)       5 (10%)      7 (14%)                               
   Skin                                               (49)         (50)         (50)         (50)                                   
      Keratoacanthoma                                  1 (2%)                                 1 (2%)                                
      Lipoma                                                                     1 (2%)                                             
      Trichoepithelioma                                                                       1 (2%)                                
      Pinna, Schwannoma Benign                                      1 (2%)                                                          
      Sebaceous Gland, Adenoma                                                                2 (4%)                                
      Sebaceous Gland, Carcinoma                       1 (2%)                                                                       
      Subcutaneous Tissue, Fibroma                                               1 (2%)       2 (4%)                                
      Subcutaneous Tissue, Fibrous Histiocytoma                     1 (2%)                                                          
      Subcutaneous Tissue, Lipoma                                                             1 (2%)                                
      Subcutaneous Tissue, Osteosarcoma                                          1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (49)         (50)         (50)         (50)                                   
      Rib, Osteosarcoma                                             1 (2%)                                                          
      Vertebra, Chordoma                                                         1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (49)         (49)         (50)         (50)                                   
      Astrocytoma Malignant                                                                   1 (2%)                                
      Carcinoma, Metastatic, Pituitary Gland                        1 (2%)                                                          
      Granular Cell Tumor Benign                       1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page   4                                                               
NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (49)         (50)         (48)         (50)                                   
   Lung                                               (49)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     1 (2%)                                 3 (6%)                                
      Alveolar/Bronchiolar Carcinoma                   1 (2%)                                                                       
      Chordoma, Metastatic, Tissue NOS                                           1 (2%)       1 (2%)                                
      Fibrous Histiocytoma, Metastatic, Skin                        1 (2%)                                                          
   Nose                                               (49)         (50)         (49)         (50)                                   
      Sarcoma                                                       1 (2%)                                                          
   Pleura                                             (1)          (1)                                                              
      Osteosarcoma, Metastatic, Bone                                1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (49)         (49)         (50)         (50)                                   
      Renal Tubule, Adenoma                                         1 (2%)                                                          
   Urinary Bladder                                    (49)         (49)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Leukemia Mononuclear                            12 (24%)     19 (38%)     18 (36%)     25 (50%)                               
      Lymphoma Malignant                                                         2 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                             Page   5                                                               
NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            48          49          50          49                                       
     Total Primary Neoplasms                           97          98         102         113                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 44          37          44          41                                       
     Total Benign Neoplasms                            73          64          69          79                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              21          30          25          30                                       
     Total Malignant Neoplasms                         24          34          33          34                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms                          3           1           1                                       
     Total Metastatic Neoplasm                                     11           1           1                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
b  Primary tumors: all tumors except metastatic tumors                                                                              
                                                             Page   6                                                               
NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                      3            3            5            5                                     
    Moribund Sacrifice                                35           32           34           35                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                12           15           11           10                                     
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (50)         (49)         (49)         (50)                                   
      Polyp Adenomatous                                                          1 (2%)                                             
   Intestine Large, Rectum                            (50)         (47)         (49)         (50)                                   
      Polyp Adenomatous                                             1 (2%)                                                          
   Intestine Large, Cecum                             (47)         (49)         (48)         (48)                                   
   Intestine Small, Duodenum                          (50)         (49)         (49)         (49)                                   
   Intestine Small, Ileum                             (48)         (49)         (48)         (47)                                   
      Carcinoma                                        1 (2%)                    1 (2%)                                             
   Liver                                              (50)         (49)         (50)         (50)                                   
      Hepatocellular Carcinoma                                      2 (4%)                                                          
   Mesentery                                          (11)         (12)         (8)          (10)                                   
   Oral Mucosa                                                     (3)          (2)          (2)                                    
      Squamous Cell Papilloma                                       1 (33%)                   1 (50%)                               
      Pharyngeal, Squamous Cell Papilloma                                        1 (50%)                                            
   Pancreas                                           (50)         (48)         (50)         (50)                                   
      Adenoma                                                       1 (2%)                                                          
   Stomach, Forestomach                               (50)         (49)         (50)         (50)                                   
      Leiomyosarcoma                                                1 (2%)                                                          
   Stomach, Glandular                                 (50)         (49)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (49)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (49)         (50)         (50)                                   
   Adrenal Medulla                                    (49)         (49)         (50)         (50)                                   
      Pheochromocytoma Malignant                       3 (6%)                    1 (2%)       1 (2%)                                
      Pheochromocytoma Benign                          7 (14%)     11 (22%)      9 (18%)     11 (22%)                               
      Bilateral, Pheochromocytoma Benign               4 (8%)       1 (2%)       3 (6%)       4 (8%)                                
                                                             Page   7                                                               
NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - cont                                                                                                             
   Islets, Pancreatic                                 (50)         (49)         (50)         (50)                                   
      Adenoma                                          1 (2%)       3 (6%)       1 (2%)       3 (6%)                                
      Carcinoma                                        2 (4%)       1 (2%)       1 (2%)       1 (2%)                                
   Pituitary Gland                                    (50)         (49)         (49)         (50)                                   
      Pars Distalis, Adenoma                          41 (82%)     27 (55%)     37 (76%)     34 (68%)                               
   Thyroid Gland                                      (50)         (49)         (50)         (50)                                   
      Bilateral, C-Cell, Adenoma                                                              1 (2%)                                
      C-Cell, Adenoma                                  1 (2%)       1 (2%)       4 (8%)       1 (2%)                                
      C-Cell, Adenoma, Multiple                                     1 (2%)                                                          
      C-Cell, Carcinoma                                3 (6%)       1 (2%)       1 (2%)       1 (2%)                                
      Follicular Cell, Carcinoma                                                 2 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                         (2)                                    (1)                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (49)         (50)         (50)                                   
   Preputial Gland                                    (50)         (49)         (50)         (50)                                   
      Adenoma                                                       2 (4%)       1 (2%)                                             
      Carcinoma                                        2 (4%)       2 (4%)       4 (8%)       3 (6%)                                
   Prostate                                           (50)         (49)         (50)         (50)                                   
   Seminal Vesicle                                    (50)         (49)         (50)         (50)                                   
   Testes                                             (50)         (50)         (50)         (50)                                   
      Bilateral, Interstitial Cell, Adenoma           18 (36%)     31 (62%)     20 (40%)     16 (32%)                               
      Interstitial Cell, Adenoma                      12 (24%)     12 (24%)     10 (20%)     20 (40%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (49)         (50)         (50)                                   
   Lymph Node                                         (15)         (10)         (6)          (7)                                    
   Lymph Node, Bronchial                              (50)         (46)         (49)         (50)                                   
   Lymph Node, Mandibular                             (46)         (46)         (44)         (44)                                   
   Lymph Node, Mesenteric                             (50)         (49)         (50)         (50)                                   
   Lymph Node, Mediastinal                            (49)         (49)         (50)         (50)                                   
   Spleen                                             (50)         (49)         (50)         (50)                                   
      Fibrosarcoma                                                               1 (2%)                                             
      Hemangiosarcoma                                                                         1 (2%)                                
   Thymus                                             (50)         (49)         (50)         (49)                                   
      Thymoma Benign                                                             1 (2%)                                             
      Thymoma Malignant                                                          2 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page   8                                                               
NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (49)         (50)         (50)                                   
      Fibroadenoma                                     1 (2%)       2 (4%)       1 (2%)       1 (2%)                                
   Skin                                               (50)         (50)         (50)         (50)                                   
      Basal Cell Adenoma                                            1 (2%)                                                          
      Keratoacanthoma                                  1 (2%)       4 (8%)       3 (6%)       2 (4%)                                
      Schwannoma Malignant                                                       1 (2%)                                             
      Squamous Cell Papilloma                                       2 (4%)                                                          
      Trichoepithelioma                                             1 (2%)       1 (2%)                                             
      Epidermis, Keratoacanthoma                       1 (2%)                                                                       
      Sebaceous Gland, Adenoma                         1 (2%)                                                                       
      Subcutaneous Tissue, Fibroma                     3 (6%)       1 (2%)       1 (2%)       4 (8%)                                
      Subcutaneous Tissue, Fibrosarcoma                             1 (2%)       1 (2%)                                             
      Subcutaneous Tissue, Lipoma                      1 (2%)                    1 (2%)                                             
      Subcutaneous Tissue, Sarcoma                                                            1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Skeletal Muscle                                                 (1)                                                              
      Sarcoma                                                       1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
   Spinal Cord                                                     (1)          (1)          (1)                                    
      Schwannoma Malignant                                                       1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (49)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     1 (2%)                                 2 (4%)                                
      Epithelioma Benign                                                         1 (2%)                                             
   Nose                                               (50)         (49)         (49)         (50)                                   
      Adenoma                                                                    1 (2%)                                             
      Vomeronasal Organ, Adenoma                                                              1 (2%)                                
   Pleura                                             (1)                       (1)                                                 
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Zymbal's Gland                                     (2)          (1)          (1)          (1)                                    
      Carcinoma                                        1 (50%)      1 (100%)     1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page   9                                                               
NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (49)         (50)         (50)                                   
   Urinary Bladder                                    (50)         (48)         (50)         (50)                                   
      Transitional Epithelium, Carcinoma                            1 (2%)                                                          
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Leukemia Mononuclear                            33 (66%)     32 (64%)     23 (46%)     34 (68%)                               
      Lymphoma Malignant                               1 (2%)       1 (2%)                                                          
      Mesothelioma Benign                                                                     1 (2%)                                
      Mesothelioma Malignant                           2 (4%)                    1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                             Page  10                                                               
NTP Experiment-Test: 60968-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:52:52  
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         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
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TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            50          49          49          50                                       
     Total Primary Neoplasms                          141         147         138         145                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 47          49          46          49                                       
     Total Benign Neoplasms                            93         103          97         102                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              40          38          33          36                                       
     Total Malignant Neoplasms                         48          44          41          43                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms                                                                                          
     Total Metastatic Neoplasm                                                                                                      
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    
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a  Number of animals examined microscopically at site and number of animals with lesion                                             
b  Primary tumors: all tumors except metastatic tumors                                                                              
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