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TDMS Study 05200-05 Pathology Tables

NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29




       Facility:  Battelle Northwest

       Chemical CAS #:  75-52-5

       Lock Date:  06/22/92

       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: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 

  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                      5            5            2            2                                     
    Moribund Sacrifice                                17           26           18           25                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                28           19           30           23                                     

  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (50)         (50)         (50)         (50)                                   
   Intestine Large, Cecum                             (50)         (50)         (50)         (50)                                   
   Intestine Small, Duodenum                          (50)         (50)         (50)         (50)                                   
   Intestine Small, Jejunum                           (50)         (50)         (50)         (50)                                   
   Intestine Small, Ileum                             (50)         (50)         (50)         (50)                                   
   Liver                                              (50)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Islets, Pancreatic                     1 (2%)                                                          
      Hepatocellular Adenoma                           1 (2%)       1 (2%)                                                          
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Mesentery                                          (10)         (11)         (12)         (14)                                   
      Carcinoma, Metastatic, Islets, Pancreatic                     1 (9%)                                                          
      Carcinoma, Metastatic, Urinary Bladder                                                  1 (7%)                                
      Histiocytic Sarcoma                                                                     1 (7%)                                
   Oral Mucosa                                        (1)                       (1)          (1)                                    
      Pharyngeal, Squamous Cell Papilloma              1 (100%)                  1 (100%)     1 (100%)                              
   Pancreas                                           (50)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Urinary Bladder                                                  1 (2%)                                
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
   Stomach, Forestomach                               (50)         (50)         (50)         (50)                                   
   Stomach, Glandular                                 (50)         (50)         (50)         (50)                                   
   Tongue                                                                       (1)                                                 
      Squamous Cell Carcinoma                                                    1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    

                                                             Page   2                                                               
NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
   Adrenal Medulla                                    (49)         (50)         (49)         (50)                                   
      Pheochromocytoma Malignant                                                 1 (2%)                                             
      Pheochromocytoma Complex                         1 (2%)                                                                       
      Pheochromocytoma Benign                                       1 (2%)       2 (4%)       2 (4%)                                
      Bilateral, Pheochromocytoma Benign               1 (2%)                                 2 (4%)                                
   Islets, Pancreatic                                 (50)         (50)         (50)         (50)                                   
      Adenoma                                          1 (2%)       1 (2%)       3 (6%)       1 (2%)                                
      Carcinoma                                                     1 (2%)                                                          
   Parathyroid Gland                                  (50)         (49)         (50)         (48)                                   
      Adenoma                                                                    1 (2%)                                             
   Pituitary Gland                                    (50)         (50)         (50)         (50)                                   
      Pars Distalis, Adenoma                          33 (66%)     36 (72%)     39 (78%)     40 (80%)                               
      Pars Distalis, Carcinoma                                                   1 (2%)                                             
   Thyroid Gland                                      (50)         (50)         (50)         (49)                                   
      Bilateral, C-Cell, Adenoma                                                 1 (2%)                                             
      C-Cell, Adenoma                                  8 (16%)      9 (18%)      7 (14%)     10 (20%)                               
      C-Cell, Carcinoma                                2 (4%)                                 3 (6%)                                
      Follicular Cell, Adenoma                                      1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (47)         (46)         (47)         (48)                                   
      Adenoma                                          6 (13%)      4 (9%)       5 (11%)      2 (4%)                                
      Carcinoma                                                     1 (2%)       3 (6%)                                             
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Bilateral, Adenoma                               1 (2%)                    1 (2%)                                             
   Ovary                                              (50)         (50)         (50)         (50)                                   
      Granulosa Cell Tumor Benign                                   1 (2%)       1 (2%)                                             
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Uterus                                             (50)         (50)         (50)         (50)                                   
      Leiomyoma                                        1 (2%)                                                                       
      Polyp Stromal                                    5 (10%)     11 (22%)      6 (12%)      5 (10%)                               
      Polyp Stromal, Multiple                          1 (2%)                                 1 (2%)                                
      Sarcoma Stromal                                               1 (2%)       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    

                                                             Page   3                                                               
NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
   Lymph Node                                         (7)          (6)          (9)          (3)                                    
   Lymph Node, Bronchial                              (48)         (49)         (47)         (48)                                   
      Carcinoma, Metastatic, Thyroid Gland                                                    1 (2%)                                
   Lymph Node, Mandibular                             (49)         (48)         (48)         (47)                                   
   Lymph Node, Mesenteric                             (50)         (50)         (49)         (50)                                   
   Lymph Node, Mediastinal                            (48)         (49)         (50)         (46)                                   
   Spleen                                             (50)         (49)         (50)         (50)                                   
   Thymus                                             (48)         (47)         (45)         (48)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (50)         (50)         (50)                                   
      Adenoma                                          2 (4%)                                 2 (4%)                                
      Carcinoma                                        2 (4%)       4 (8%)       1 (2%)      10 (20%)                               
      Carcinoma, Multiple                                           3 (6%)                    1 (2%)                                
      Fibroadenoma                                    10 (20%)     15 (30%)     19 (38%)     22 (44%)                               
      Fibroadenoma, Multiple                           9 (18%)      6 (12%)     14 (28%)     14 (28%)                               
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Sarcoma, Metastatic, Skin                                     1 (2%)                                                          
   Skin                                               (50)         (50)         (48)         (49)                                   
      Squamous Cell Carcinoma                                                    1 (2%)                                             
      Squamous Cell Papilloma                          1 (2%)       1 (2%)                    1 (2%)                                
      Subcutaneous Tissue, Fibroma                     1 (2%)       1 (2%)                                                          
      Subcutaneous Tissue, Fibrosarcoma                             1 (2%)                    1 (2%)                                
      Subcutaneous Tissue, Histiocytic Sarcoma                                                1 (2%)                                
      Subcutaneous Tissue, Sarcoma                                  1 (2%)                    2 (4%)                                
      Subcutaneous Tissue, Schwannoma Malignant                                  1 (2%)                                             
      Subcutaneous Tissue, Pinna, Amelanotic                                                                                        
          Melanoma, Malignant                                                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Osteosarcoma                                     1 (2%)                                                                       
   Skeletal Muscle                                    (1)          (2)                       (1)                                    
      Carcinoma, Metastatic, Urinary Bladder                                                  1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    

                                                             Page   4                                                               
NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Astrocytoma Benign                               1 (2%)                                                                       
      Carcinoma, Metastatic, Pituitary Gland                                     1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (50)         (50)         (49)                                   
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                                  1 (2%)       1 (2%)       1 (2%)                                
      Alveolar/Bronchiolar Carcinoma                   1 (2%)                                                                       
      Carcinoma, Metastatic, Islets, Pancreatic                     1 (2%)                                                          
      Carcinoma, Metastatic, Mammary Gland                          1 (2%)       1 (2%)                                             
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Osteosarcoma, Metastatic, Bone                   1 (2%)                                                                       
   Nose                                               (50)         (50)         (50)         (50)                                   
   Trachea                                            (50)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Lung                      1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (3)                                                                           
   Zymbal's Gland                                     (1)          (1)                       (1)                                    
      Carcinoma                                        1 (100%)     1 (100%)                  1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Urinary Bladder                                                  1 (2%)                                
      Lipoma                                                        1 (2%)                                                          
      Mesenchymal Tumor Malignant                                                             1 (2%)                                
      Renal Tubule, Carcinoma                          1 (2%)                                                                       
   Urinary Bladder                                    (50)         (50)         (49)         (50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Transitional Epithelium, Carcinoma                                                      1 (2%)                                
      Transitional Epithelium, Papilloma                                         2 (4%)                                             
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   

   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Leukemia Mononuclear                            22 (44%)     13 (26%)     14 (28%)      9 (18%)                               
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 

                                                             Page   5                                                               
NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 SYSTEMIC LESIONS - cont                                                                                                            

   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
____________________________________________________________________________________________________________________________________

                                                             Page   6                                                               
NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            49          50          50          50                                       
     Total Primary Neoplasms                          114         116         127         135                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 44          47          48          49                                       
     Total Benign Neoplasms                            83          90         103         104                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              28          21          20          27                                       
     Total Malignant Neoplasms                         31          26          24          31                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              2           3           2           2                                       
     Total Metastatic Neoplasm                          2           5           2           5                                       
                                                                                                                                    
   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: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 

  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                33           31           34           39                                     
    Natural Death                                      4            3            2            3                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                13           16           14            8                                     

  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (50)         (50)         (50)         (50)                                   
   Intestine Large, Rectum                            (50)         (49)         (50)         (49)                                   
   Intestine Large, Cecum                             (50)         (50)         (50)         (50)                                   
   Intestine Small, Duodenum                          (50)         (50)         (50)         (49)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Intestine Small, Jejunum                           (50)         (50)         (50)         (50)                                   
   Intestine Small, Ileum                             (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Liver                                              (50)         (50)         (50)         (50)                                   
      Cholangiocarcinoma                               1 (2%)                                                                       
      Hepatocellular Carcinoma                                                   2 (4%)                                             
      Hepatocellular Adenoma                           1 (2%)       1 (2%)                    2 (4%)                                
      Hepatocellular Adenoma, Multiple                                           1 (2%)                                             
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                                                          
   Mesentery                                          (15)         (13)         (10)         (8)                                    
   Oral Mucosa                                        (1)          (2)          (1)                                                 
      Pharyngeal, Squamous Cell Papilloma                           1 (50%)      1 (100%)                                           
   Pancreas                                           (50)         (50)         (50)         (50)                                   
      Adenoma                                          1 (2%)       1 (2%)       1 (2%)                                             
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
   Stomach, Forestomach                               (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Stomach, Glandular                                 (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Tongue                                                          (1)                       (1)                                    
      Squamous Cell Carcinoma                                       1 (100%)                                                        
      Squamous Cell Papilloma                                                                 1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    

                                                             Page   8                                                               
NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Schwannoma Malignant                             1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Carcinoma                                                                               1 (2%)                                
      Carcinoma, Metastatic, Zymbal's Gland                                                   1 (2%)                                
      Pheochromocytoma Malignant, Metastatic,                                                                                       
          Adrenal Medulla                                           1 (2%)                                                          
   Adrenal Medulla                                    (50)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Zymbal's Gland                                                   1 (2%)                                
      Pheochromocytoma Malignant                                    1 (2%)       2 (4%)       2 (4%)                                
      Pheochromocytoma Benign                         11 (22%)     12 (24%)     15 (30%)     14 (28%)                               
      Bilateral, Pheochromocytoma Malignant            1 (2%)                                                                       
      Bilateral, Pheochromocytoma Benign               5 (10%)      8 (16%)      6 (12%)      5 (10%)                               
   Islets, Pancreatic                                 (50)         (50)         (50)         (50)                                   
      Adenoma                                          8 (16%)      9 (18%)      4 (8%)       1 (2%)                                
      Carcinoma                                        1 (2%)       1 (2%)       3 (6%)       5 (10%)                               
   Parathyroid Gland                                  (47)         (49)         (49)         (48)                                   
      Adenoma                                                       1 (2%)       1 (2%)                                             
   Pituitary Gland                                    (50)         (47)         (50)         (49)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
      Pars Distalis, Adenoma                          38 (76%)     36 (77%)     32 (64%)     39 (80%)                               
      Pars Intermedia, Adenoma                                                   1 (2%)       2 (4%)                                
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Bilateral, C-Cell, Carcinoma                                  1 (2%)                                                          
      C-Cell, Adenoma                                  8 (16%)      5 (10%)      8 (16%)      8 (16%)                               
      C-Cell, Carcinoma                                             1 (2%)       1 (2%)       3 (6%)                                
      Follicular Cell, Adenoma                                      1 (2%)                                                          
      Follicular Cell, Carcinoma                       1 (2%)       1 (2%)       2 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                                      (1)                       (1)                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (50)         (50)         (50)                                   
   Preputial Gland                                    (50)         (50)         (50)         (50)                                   
      Adenoma                                          4 (8%)       3 (6%)       3 (6%)       3 (6%)                                
      Carcinoma                                                     1 (2%)       1 (2%)       1 (2%)                                
   Prostate                                           (50)         (50)         (50)         (50)                                   

                                                             Page   9                                                               
NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - cont                                                                                                               
   Seminal Vesicle                                    (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Testes                                             (50)         (50)         (50)         (50)                                   
      Bilateral, Interstitial Cell, Adenoma           22 (44%)     23 (46%)     27 (54%)     16 (32%)                               
      Interstitial Cell, Adenoma                      16 (32%)     11 (22%)     13 (26%)     15 (30%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                                                          
   Lymph Node                                         (17)         (13)         (17)         (13)                                   
      Deep Cervical, Carcinoma, Metastatic,                                                                                         
          Thyroid Gland                                             1 (8%)                                                          
      Iliac, Histiocytic Sarcoma                                    1 (8%)                                                          
      Renal, Histiocytic Sarcoma                                    1 (8%)                                                          
   Lymph Node, Bronchial                              (48)         (48)         (48)         (47)                                   
      Osteosarcoma, Metastatic, Bone                                1 (2%)                                                          
   Lymph Node, Mandibular                             (48)         (48)         (48)         (49)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Lymph Node, Mesenteric                             (50)         (50)         (48)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Lymph Node, Mediastinal                            (50)         (45)         (50)         (47)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Spleen                                             (50)         (50)         (50)         (50)                                   
      Fibroma                                          1 (2%)       1 (2%)                                                          
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Thymus                                             (45)         (45)         (48)         (46)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
      Thymoma Benign                                                             1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (28)         (27)         (31)         (28)                                   
      Fibroadenoma                                     1 (4%)       1 (4%)       1 (3%)       2 (7%)                                
   Skin                                               (50)         (49)         (50)         (50)                                   
      Basal Cell Carcinoma                                                                    2 (4%)                                
      Keratoacanthoma                                  6 (12%)      2 (4%)       2 (4%)       1 (2%)                                
      Keratoacanthoma, Multiple                                                               1 (2%)                                
      Squamous Cell Carcinoma                          1 (2%)       2 (4%)       1 (2%)       1 (2%)                                
      Squamous Cell Papilloma                                                                 3 (6%)                                
      Sebaceous Gland, Adenoma                         1 (2%)       1 (2%)                                                          
      Subcutaneous Tissue, Fibroma                     3 (6%)                    1 (2%)                                             
      Subcutaneous Tissue, Fibrosarcoma                3 (6%)                                                                       
      Subcutaneous Tissue, Lipoma                                                             1 (2%)                                
      Subcutaneous Tissue, Osteosarcoma                                          1 (2%)                                             

                                                             Page  10                                                               
NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
INTEGUMENTARY SYSTEM - cont                                                                                                         
      Subcutaneous Tissue, Sarcoma                                               2 (4%)                                             
      Subcutaneous Tissue, Schwannoma Malignant                                               2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Osteoma                                          1 (2%)                                                                       
      Osteosarcoma                                                  1 (2%)                                                          
   Skeletal Muscle                                    (2)                       (1)          (1)                                    
      Histiocytic Sarcoma                              1 (50%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Granular Cell Tumor Benign                                                              1 (2%)                                
      Oligodendroglioma Benign                                      1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (50)         (50)         (50)                                   
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     1 (2%)       2 (4%)                    3 (6%)                                
      Alveolar/Bronchiolar Carcinoma                                             2 (4%)                                             
      Carcinoma, Metastatic, Thyroid Gland                          1 (2%)                                                          
      Carcinoma, Metastatic, Zymbal's Gland                                                   1 (2%)                                
      Cholangiocarcinoma, Metastatic, Liver            1 (2%)                                                                       
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                                                          
      Osteosarcoma, Metastatic, Bone                                1 (2%)                                                          
      Pheochromocytoma Malignant, Metastatic,                                                                                       
          Adrenal Medulla                              1 (2%)                                                                       
      Squamous Cell Carcinoma, Metastatic, Skin                                  1 (2%)                                             
   Nose                                               (50)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (1)                                                                           
   Zymbal's Gland                                                  (2)                       (1)                                    
      Carcinoma                                                     2 (100%)                  1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    

                                                             Page  11                                                               
NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Zymbal's Gland                                                   1 (2%)                                
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                                                          
      Lipoma                                                                     1 (2%)                                             
      Renal Tubule, Adenoma                                         3 (6%)       2 (4%)       1 (2%)                                
   Urinary Bladder                                    (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
      Transitional Epithelium, Papilloma                            1 (2%)                                                          
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   

   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                                                          
      Leukemia Mononuclear                            35 (70%)     27 (54%)     33 (66%)     25 (50%)                               
      Mesothelioma Malignant                           1 (2%)       3 (6%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________

                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 

                                                             Page  12                                                               
NTP Experiment-Test: 05200-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            NITROMETHANE                                       Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 05:30:29  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      94 PPM       188 PPM      375 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            50          49          50          49                                       
     Total Primary Neoplasms                          174         167         171         163                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 50          45          50          47                                       
     Total Benign Neoplasms                           128         124         121         119                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              40          35          39          33                                       
     Total Malignant Neoplasms                         46          43          50          44                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              2           3           1           1                                       
     Total Metastatic Neoplasm                          2           5           1           4                                       
                                                                                                                                    
   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  13                                                               
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