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TDMS Study 97006-01 Pathology Tables

NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56

                                                          FINAL#1/RATS




       Facility:  Battelle Northwest

       Chemical CAS #:  108-10-1

       Lock Date:  01/24/03

       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

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NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                14           14           20           15                                     
    Natural Death                                      1            2            4            3                                     
  Survivors                                                                                                                         
    Moribund Sacrifice                                              1                                                               
    Terminal Sacrifice                                35           33           26           32                                     
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (50)         (49)         (49)         (50)                                   
      Adenoma                                                                                 1 (2%)                                
   Liver                                              (50)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Adrenal Cortex                         1 (2%)                                                          
      Hepatocellular Adenoma                                        1 (2%)       1 (2%)                                             
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Mesentery                                          (18)         (17)         (15)         (15)                                   
      Histiocytic Sarcoma                                                                     1 (7%)                                
      Schwannoma Malignant                                          1 (6%)                                                          
   Oral Mucosa                                                     (1)                                                              
      Squamous Cell Carcinoma                                       1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Carcinoma                                                     1 (2%)                                                          
   Adrenal Medulla                                    (50)         (50)         (50)         (50)                                   
      Pheochromocytoma Malignant                                    1 (2%)       1 (2%)                                             
      Pheochromocytoma Benign                          3 (6%)                    2 (4%)       2 (4%)                                
   Islets, Pancreatic                                 (50)         (50)         (50)         (50)                                   
      Adenoma                                                                                 1 (2%)                                
   Pituitary Gland                                    (49)         (50)         (50)         (50)                                   
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   2                                                               
                                                                                                                                   
NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - cont                                                                                                             
      Adenoma                                         24 (49%)     28 (56%)     26 (52%)     30 (60%)                               
      Carcinoma                                                                  1 (2%)                                             
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Bilateral, C-Cell, Adenoma                                    1 (2%)                                                          
      C-Cell, Adenoma                                  3 (6%)       1 (2%)       2 (4%)       2 (4%)                                
      C-Cell, Carcinoma                                1 (2%)       1 (2%)       1 (2%)       2 (4%)                                
      Follicular Cell, Adenoma                         1 (2%)                    1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (50)         (50)         (50)         (50)                                   
      Carcinoma                                        1 (2%)       3 (6%)       1 (2%)       3 (6%)                                
   Ovary                                              (50)         (50)         (50)         (50)                                   
      Cystadenocarcinoma                                                         1 (2%)                                             
      Cystadenocarcinoma, Metastatic, Ovary                                      1 (2%)                                             
      Granulosa Cell Tumor Benign                                                             1 (2%)                                
      Thecoma Malignant                                                                       1 (2%)                                
   Uterus                                             (50)         (50)         (50)         (50)                                   
      Carcinoma                                                                               1 (2%)                                
      Hemangioma                                                                              1 (2%)                                
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Leiomyosarcoma                                                1 (2%)                                                          
      Polyp Stromal                                   11 (22%)      4 (8%)       7 (14%)     13 (26%)                               
      Polyp Stromal, Multiple                                                                 1 (2%)                                
      Sarcoma Stromal                                  1 (2%)                                 1 (2%)                                
      Bilateral, Polyp Stromal                                      1 (2%)       1 (2%)                                             
      Cervix, Polyp Stromal                            1 (2%)                                                                       
      Serosa, Hemangioma                                            1 (2%)                                                          
   Vagina                                             (2)                                    (1)                                    
      Histiocytic Sarcoma                              1 (50%)                                                                      
      Sarcoma                                          1 (50%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   3                                                               
                                                                                                                                   
NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
   Lymph Node                                         (1)          (2)          (2)          (3)                                    
      Deep Cervical, Carcinoma, Metastatic,                                                                                         
          Thyroid Gland                                                          1 (50%)      1 (33%)                               
   Lymph Node, Bronchial                              (9)          (12)         (8)          (7)                                    
      Carcinoma, Metastatic, Thyroid Gland                          1 (8%)                    1 (14%)                               
      Cystadenocarcinoma, Metastatic, Ovary                                      1 (13%)                                            
      Sarcoma, Metastatic, Skin                                                               1 (14%)                               
   Lymph Node, Mandibular                             (1)                       (2)          (1)                                    
   Lymph Node, Mesenteric                             (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Lymph Node, Mediastinal                            (46)         (44)         (46)         (49)                                   
      Carcinoma, Metastatic, Zymbal's Gland                                                   1 (2%)                                
      Cystadenocarcinoma, Metastatic, Ovary                                      1 (2%)                                             
   Spleen                                             (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Thymus                                             (47)         (49)         (49)         (49)                                   
      Cystadenocarcinoma, Metastatic, Ovary                                      1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (50)         (50)         (50)                                   
      Carcinoma                                        5 (10%)      8 (16%)      6 (12%)      4 (8%)                                
      Fibroadenoma                                    17 (34%)     11 (22%)     18 (36%)     10 (20%)                               
      Fibroadenoma, Multiple                           5 (10%)      8 (16%)      7 (14%)      8 (16%)                               
   Skin                                               (50)         (50)         (50)         (50)                                   
      Basal Cell Carcinoma                                          1 (2%)                                                          
      Schwannoma Malignant                                                                    1 (2%)                                
      Squamous Cell Papilloma                                                    1 (2%)                                             
      Subcutaneous Tissue, Fibroma                                               1 (2%)                                             
      Subcutaneous Tissue, Fibrosarcoma                             1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Cranium, Carcinoma, Metastatic, Pituitary                                                                                     
          Gland                                                                  1 (2%)                                             
   Skeletal Muscle                                    (10)         (5)          (8)          (14)                                   
      Cystadenocarcinoma, Metastatic, Ovary                                      1 (13%)                                            
      Sarcoma                                                                    1 (13%)                                            
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   4                                                               
                                                                                                                                   
NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
MUSCULOSKELETAL SYSTEM - cont                                                                                                       
      Schwannoma Malignant                                          1 (20%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Pineal Gland, Adenoma                                         1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     1 (2%)       1 (2%)                                                          
      Carcinoma, Metastatic, Clitoral Gland                                      1 (2%)       1 (2%)                                
      Carcinoma, Metastatic, Thyroid Gland                                       1 (2%)       1 (2%)                                
      Carcinoma, Metastatic, Zymbal's Gland                                                   1 (2%)                                
      Carcinoma, Metastatic, Adrenal Cortex                         1 (2%)                                                          
      Cystadenocarcinoma, Metastatic, Ovary                                      1 (2%)                                             
      Pheochromocytoma Malignant, Metastatic,                                                                                       
          Adrenal Medulla                                                        1 (2%)                                             
      Sarcoma, Metastatic, Skin                                                               1 (2%)                                
      Mediastinum, Schwannoma Malignant,                                                                                            
          Metastatic, Mesentery                                     1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (50)         (50)         (50)         (50)                                   
      Sarcoma                                                                    1 (2%)                                             
   Zymbal's Gland                                                               (3)          (1)                                    
      Carcinoma                                                                  2 (67%)      1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Cystadenocarcinoma, Metastatic, Ovary                                      1 (2%)                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   5                                                               
                                                                                                                                   
NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - cont                                                                                                               
      Mesenchymal Tumor Malignant                                                             2 (4%)                                
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
                                                                                                                                    
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                              2 (4%)                                 1 (2%)                                
      Leukemia Mononuclear                            14 (28%)     21 (42%)     12 (24%)     16 (32%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   6                                                               
                                                                                                                                   
NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            46          46          49          47                                       
     Total Primary Neoplasms                           91          99          94         103                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 44          39          40          40                                       
     Total Benign Neoplasms                            66          58          67          70                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              22          27          22          25                                       
     Total Malignant Neoplasms                         25          41          27          33                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms                          3           5           4                                       
     Total Metastatic Neoplasm                                      4          12           8                                       
                                                                                                                                    
   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   7                                                               
                                                                                                                                   
NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                14           16           21           29                                     
    Natural Death                                      4            5            4            2                                     
    Accidently Killed                                               1                                                               
  Survivors                                                                                                                         
    Terminal Sacrifice                                32           28           25           19                                     
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Rectum                            (49)         (48)         (50)         (50)                                   
      Adenoma                                                                    1 (2%)                                             
   Liver                                              (50)         (50)         (50)         (50)                                   
      Hepatocellular Adenoma                           1 (2%)                                 1 (2%)                                
      Histiocytic Sarcoma                                           2 (4%)                                                          
   Oral Mucosa                                        (2)                                                                           
      Squamous Cell Carcinoma                          1 (50%)                                                                      
   Pancreas                                           (50)         (48)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (49)         (50)         (50)                                   
      Sarcoma, Metastatic, Lung                                     1 (2%)                                                          
      Schwannoma Malignant                             1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (48)         (50)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Adrenal Medulla                                    (50)         (48)         (50)         (50)                                   
      Pheochromocytoma Malignant                                    2 (4%)       1 (2%)       2 (4%)                                
      Pheochromocytoma Benign                          7 (14%)      4 (8%)       6 (12%)     11 (22%)                               
      Bilateral, Pheochromocytoma Benign               1 (2%)       3 (6%)       4 (8%)       1 (2%)                                
   Islets, Pancreatic                                 (50)         (48)         (50)         (50)                                   
      Adenoma                                          3 (6%)       4 (8%)       1 (2%)       1 (2%)                                
      Carcinoma                                        4 (8%)       2 (4%)       2 (4%)       1 (2%)                                
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   8                                                               
                                                                                                                                   
NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - cont                                                                                                             
   Pituitary Gland                                    (50)         (49)         (50)         (50)                                   
      Adenoma                                         35 (70%)     29 (59%)     30 (60%)     29 (58%)                               
   Thyroid Gland                                      (50)         (48)         (50)         (50)                                   
      C-Cell, Adenoma                                  1 (2%)       4 (8%)                    4 (8%)                                
      C-Cell, Carcinoma                                2 (4%)       3 (6%)                    1 (2%)                                
      Follicular Cell, Carcinoma                       1 (2%)       2 (4%)       2 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                         (48)         (46)         (49)         (49)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (49)         (50)         (50)                                   
   Preputial Gland                                    (50)         (49)         (50)         (50)                                   
      Carcinoma                                        1 (2%)                    1 (2%)                                             
   Testes                                             (50)         (50)         (50)         (50)                                   
      Bilateral, Interstitial Cell, Adenoma           28 (56%)     34 (68%)     37 (74%)     38 (76%)                               
      Interstitial Cell, Adenoma                      14 (28%)      8 (16%)      7 (14%)     10 (20%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (49)         (50)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Lymph Node                                         (7)          (7)          (12)         (15)                                   
      Deep Cervical, Carcinoma, Metastatic,                                                                                         
          Thyroid Gland                                             1 (14%)                   1 (7%)                                
   Lymph Node, Bronchial                              (11)         (13)         (12)         (7)                                    
      Carcinoma, Metastatic, Thyroid Gland                                       1 (8%)                                             
      Sarcoma, Metastatic, Lung                                     1 (8%)                                                          
   Lymph Node, Mandibular                             (1)          (1)          (3)          (2)                                    
   Lymph Node, Mesenteric                             (50)         (48)         (50)         (50)                                   
   Lymph Node, Mediastinal                            (41)         (44)         (46)         (44)                                   
      Carcinoma, Metastatic, Thyroid Gland                          1 (2%)                                                          
      Sarcoma, Metastatic, Lung                                     1 (2%)                                                          
   Spleen                                             (50)         (50)         (50)         (50)                                   
      Hemangioma                                       1 (2%)                                                                       
      Histiocytic Sarcoma                                           1 (2%)                                                          
      Schwannoma Malignant, Metastatic, Heart          1 (2%)                                                                       
   Thymus                                             (49)         (47)         (50)         (49)                                   
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   9                                                               
                                                                                                                                   
NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
      Carcinoma, Metastatic, Thyroid Gland                          1 (2%)                                                          
      Schwannoma Malignant, Metastatic, Heart          1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (49)         (49)         (50)         (50)                                   
      Carcinoma                                        2 (4%)       1 (2%)                    1 (2%)                                
      Fibroadenoma                                     2 (4%)       2 (4%)       2 (4%)       1 (2%)                                
   Skin                                               (50)         (49)         (50)         (50)                                   
      Basal Cell Adenoma                                                                      1 (2%)                                
      Basal Cell Carcinoma                                          1 (2%)                                                          
      Fibrous Histiocytoma                                                                    1 (2%)                                
      Keratoacanthoma                                                            1 (2%)                                             
      Sarcoma                                                       1 (2%)                    1 (2%)                                
      Squamous Cell Papilloma                                                    1 (2%)                                             
      Sebaceous Gland, Adenoma                         1 (2%)                                 1 (2%)                                
      Subcutaneous Tissue, Fibroma                     4 (8%)       1 (2%)       2 (4%)       2 (4%)                                
      Subcutaneous Tissue, Fibrosarcoma                1 (2%)       2 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Skeletal Muscle                                    (3)          (3)          (4)          (6)                                    
      Sarcoma, Metastatic, Lung                                     1 (33%)                                                         
      Schwannoma Malignant, Metastatic, Heart          1 (33%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (49)         (50)         (50)                                   
      Glioma Malignant                                              1 (2%)                                                          
      Granular Cell Tumor Malignant                                              1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (48)         (50)         (50)                                   
      Carcinoma, Metastatic, Thyroid Gland                          1 (2%)                                                          
   Lung                                               (50)         (49)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma                                                          2 (4%)                                
      Carcinoma, Metastatic, Mammary Gland                          1 (2%)                                                          
      Carcinoma, Metastatic, Thyroid Gland                                       1 (2%)                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  10                                                               
                                                                                                                                   
NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - cont                                                                                                           
      Carcinoma, Metastatic, Zymbal's Gland                                                   1 (2%)                                
      Fibrosarcoma, Metastatic, Skin                   1 (2%)                                                                       
      Schwannoma Malignant, Metastatic, Heart          1 (2%)                                                                       
      Mediastinum, Sarcoma                                          2 (4%)                                                          
      Mediastinum, Schwannoma Malignant,                                                                                            
          Metastatic, Heart                            1 (2%)                                                                       
   Pleura                                             (50)         (49)         (50)         (50)                                   
      Schwannoma Malignant, Metastatic, Heart          1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (49)         (45)         (46)         (48)                                   
      Carcinoma, Metastatic, Oral Mucosa               1 (2%)                                                                       
   Zymbal's Gland                                     (1)                                    (2)                                    
      Carcinoma                                        1 (100%)                               2 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Renal Tubule, Adenoma                                                      2 (4%)       3 (6%)                                
      Renal Tubule, Carcinoma                                       1 (2%)                    2 (4%)                                
   Urinary Bladder                                    (50)         (48)         (50)         (50)                                   
      Leiomyoma                                                                               1 (2%)                                
      Transitional Epithelium, Papilloma               1 (2%)                                 1 (2%)                                
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
                                                                                                                                    
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                                           2 (4%)                                                          
      Leukemia Mononuclear                            25 (50%)     26 (52%)     32 (64%)     35 (70%)                               
      Mesothelioma Malignant                           1 (2%)       1 (2%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  11                                                               
                                                                                                                                   
NTP Experiment-Test: 97006-01  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 05/11/04  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            50          48          49          50                                       
     Total Primary Neoplasms                          139         136         133         154                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 50          47          47          49                                       
     Total Benign Neoplasms                            99          89          94         105                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              31          35          34          41                                       
     Total Malignant Neoplasms                         40          47          39          49                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              3           3           1           2                                       
     Total Metastatic Neoplasm                          8           9           2           2                                       
                                                                                                                                    
   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  12                                                               
                                                                                                                                   
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