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TDMS Study 88050-06 Pathology Tables

NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99
Route: GAVAGE                                                                                                     Time: 12:44:20

                                                    CORE STUDY MICE FINAL#1




       Facility:  Battelle Columbus Laboratory

       Chemical CAS #:  126-98-7

       Lock Date:  06/26/98

       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: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 

  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                     14           13            4            7                                     
    Moribund Sacrifice                                 1            2            3            3                                     
    Accidently Killed                                                                        15                                     
  Survivors                                                                                                                         
    Natural Death                                      1                                                                            
    Terminal Sacrifice                                34           35           43           25                                     

  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (50)         (50)         (50)         (50)                                   
      Periesophageal Tissue, Fibrous Histiocytoma,                                                                                  
           Metastatic, Mesentery                                                 1 (2%)                                             
      Periesophageal Tissue, Leiomyosarcoma,                                                                                        
          Metastatic, Intestine Small, Ileum                                                  1 (2%)                                
   Intestine Large, Cecum                             (50)         (50)         (50)         (50)                                   
      Adenocarcinoma                                                1 (2%)                                                          
      Leiomyoma                                        3 (6%)       1 (2%)                                                          
   Intestine Small, Duodenum                          (49)         (50)         (50)         (50)                                   
      Adenoma                                          1 (2%)       1 (2%)                                                          
   Intestine Small, Jejunum                           (50)         (50)         (50)         (50)                                   
      Sarcoma NOS, Metastatic, Uncertain Primary                                                                                    
          Site                                         1 (2%)                                                                       
   Intestine Small, Ileum                             (50)         (50)         (50)         (50)                                   
      Adenocarcinoma                                                             1 (2%)                                             
      Leiomyosarcoma                                                                          1 (2%)                                
   Liver                                              (50)         (50)         (49)         (50)                                   
      Hemangiosarcoma                                               1 (2%)                    1 (2%)                                
      Hepatocellular Carcinoma                         2 (4%)       1 (2%)       3 (6%)       1 (2%)                                
      Hepatocellular Carcinoma, Multiple                            1 (2%)       1 (2%)                                             
      Hepatocellular Adenoma                           6 (12%)      9 (18%)     11 (22%)      4 (8%)                                
      Hepatocellular Adenoma, Multiple                 3 (6%)                    1 (2%)       1 (2%)                                
      Histiocytic Sarcoma                                           1 (2%)                    1 (2%)                                
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (2%)                                
   Mesentery                                          (16)         (11)         (15)         (4)                                    
      Fibrosarcoma, Metastatic, Skin                                             1 (7%)                                             
      Fibrous Histiocytoma                                                       1 (7%)                                             
      Hepatocellular Carcinoma, Metastatic, Liver                                1 (7%)                                             
      Leiomyosarcoma, Metastatic, Uterus               1 (6%)                                                                       
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - cont                                                                                                            
           Ileum                                                                              1 (25%)                               
      Lipoma                                                                     1 (7%)                                             
      Sarcoma NOS                                      1 (6%)                                                                       
      Sarcoma NOS, Metastatic, Uncertain Primary                                                                                    
          Site                                         1 (6%)                                                                       
      Schwannoma Malignant, Metastatic, Skin           1 (6%)                                                                       
   Oral Mucosa                                        (3)          (5)          (2)          (1)                                    
      Squamous Cell Carcinoma                                                                 1 (100%)                              
      Pharyngeal, Squamous Cell Papilloma              1 (33%)                                                                      
   Pancreas                                           (50)         (50)         (50)         (48)                                   
      Fibrosarcoma, Metastatic, Skin                                             1 (2%)                                             
      Fibrous Histiocytoma, Metastatic, Mesentery                                1 (2%)                                             
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (2%)                                
   Salivary Glands                                    (48)         (50)         (50)         (49)                                   
      Fibrosarcoma, Metastatic, Skin                                             1 (2%)                                             
   Stomach, Forestomach                               (50)         (50)         (50)         (50)                                   
      Squamous Cell Papilloma                                                    1 (2%)                                             
   Stomach, Glandular                                 (50)         (50)         (50)         (50)                                   
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                  1 (2%)                                             
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (49)         (50)         (50)         (50)                                   
   Adrenal Medulla                                    (49)         (50)         (50)         (50)                                   
      Pheochromocytoma Benign                                                    1 (2%)                                             
   Pituitary Gland                                    (49)         (49)         (49)         (49)                                   
      Pars Distalis, Adenoma                           2 (4%)       1 (2%)       2 (4%)       2 (4%)                                
      Pars Intermedia, Adenoma                         2 (4%)                                 1 (2%)                                
   Thyroid Gland                                      (49)         (50)         (50)         (50)                                   
      Follicular Cell, Adenoma                                                   1 (2%)                                             
      Follicular Cell, Carcinoma                                    2 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                                                                (1)                                    
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (50)         (50)         (50)         (49)                                   
   Ovary                                              (50)         (50)         (50)         (49)                                   
      Adenocarcinoma                                                                          1 (2%)                                
      Cystadenoma                                      2 (4%)       1 (2%)       1 (2%)       1 (2%)                                
      Fibrous Histiocytoma, Metastatic, Mesentery                                1 (2%)                                             
      Hemangioma                                       2 (4%)                                                                       
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (2%)                                
      Luteoma                                                                    1 (2%)                                             
      Teratoma Benign                                  1 (2%)                                                                       
      Thecoma Malignant                                                          1 (2%)                                             
   Uterus                                             (50)         (50)         (50)         (50)                                   
      Fibrous Histiocytoma, Metastatic, Mesentery                                1 (2%)                                             
      Hemangiosarcoma                                               1 (2%)                                                          
      Leiomyoma                                        1 (2%)                                                                       
      Leiomyosarcoma                                   1 (2%)                                                                       
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (2%)                                
      Polyp Stromal                                                 1 (2%)       1 (2%)       1 (2%)                                
      Cervix, Hemangiosarcoma                                       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Fibrosarcoma, Metastatic, Skin                                             1 (2%)                                             
      Hemangiosarcoma                                                                         1 (2%)                                
   Lymph Node                                         (9)          (6)          (8)          (5)                                    
      Mediastinal, Alveolar/Bronchiolar Carcinoma,                                                                                  
           Metastatic, Lung                                                      1 (13%)                                            
      Mediastinal, Fibrosarcoma, Metastatic, Skin                                1 (13%)                                            
      Mediastinal, Sarcoma, Metastatic, Bone                                                  1 (20%)                               
      Renal, Leiomyosarcoma, Metastatic, Intestine                                                                                  
          Small, Ileum                                                                        1 (20%)                               
   Lymph Node, Mandibular                             (48)         (49)         (46)         (47)                                   
      Carcinoma, Metastatic, Harderian Gland           1 (2%)                                                                       
   Lymph Node, Mesenteric                             (47)         (48)         (47)         (46)                                   
      Histiocytic Sarcoma                                           1 (2%)                    1 (2%)                                
      Sarcoma NOS, Metastatic, Uncertain Primary                                                                                    
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
          Site                                         1 (2%)                                                                       
   Spleen                                             (50)         (50)         (49)         (49)                                   
      Hemangiosarcoma                                  1 (2%)                                 1 (2%)                                
      Hemangiosarcoma, Metastatic, Bone Marrow                                                1 (2%)                                
      Histiocytic Sarcoma                                           1 (2%)                                                          
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (2%)                                
   Thymus                                             (47)         (43)         (46)         (48)                                   
      Sarcoma, Metastatic, Bone                                                               1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (49)         (50)         (49)         (49)                                   
      Adenoacanthoma                                                             1 (2%)                                             
      Carcinoma                                                                               2 (4%)                                
      Schwannoma Malignant, Metastatic, Skin           1 (2%)                                                                       
      Duct, Adenoma                                                 1 (2%)                                                          
   Skin                                               (50)         (50)         (50)         (50)                                   
      Subcutaneous Tissue, Fibrosarcoma                2 (4%)       1 (2%)       5 (10%)      1 (2%)                                
      Subcutaneous Tissue, Liposarcoma                              1 (2%)                                                          
      Subcutaneous Tissue, Sarcoma                                  1 (2%)                                                          
      Subcutaneous Tissue, Sarcoma NOS, Metastatic,                                                                                 
           Uncertain Primary Site                      1 (2%)                                                                       
      Subcutaneous Tissue, Schwannoma Malignant        2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Fibrosarcoma, Metastatic, Skin                                             2 (4%)                                             
      Cranium, Carcinoma, Metastatic, Harderian                                                                                     
          Gland                                        1 (2%)                                                                       
      Rib, Periosteum, Sarcoma                                                                1 (2%)                                
      Vertebra, Schwannoma Malignant, Metastatic,                                                                                   
           Skin                                        1 (2%)                                                                       
   Skeletal Muscle                                    (4)          (1)          (2)                                                 
      Fibrosarcoma, Metastatic, Skin                                             2 (100%)                                           
      Leiomyosarcoma, Metastatic, Uterus               1 (25%)                                                                      
      Liposarcoma, Metastatic, Skin                                 1 (100%)                                                        
      Schwannoma Malignant, Metastatic, Skin           2 (50%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Hamartoma                                                                  1 (2%)                                             
   Spinal Cord                                        (1)                       (2)                                                 
      Fibrosarcoma, Metastatic, Skin                                             2 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     6 (12%)      3 (6%)       1 (2%)       2 (4%)                                
      Alveolar/Bronchiolar Carcinoma                   1 (2%)                    1 (2%)       3 (6%)                                
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (2%)                                
      Carcinoma, Metastatic, Harderian Gland           2 (4%)                                                                       
      Carcinoma, Metastatic, Thyroid Gland                          1 (2%)                                                          
      Fibrosarcoma, Metastatic, Skin                                             3 (6%)                                             
      Hepatocellular Carcinoma, Metastatic, Liver      2 (4%)                    3 (6%)                                             
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (2%)                                
      Liposarcoma, Metastatic, Skin                                 1 (2%)                                                          
      Sarcoma, Metastatic, Bone                                                               1 (2%)                                
      Artery, Schwannoma Malignant, Metastatic,                                                                                     
           Skin                                        1 (2%)                                                                       
      Mediastinum, Alveolar/Bronchiolar Carcinoma,                                                                                  
           Metastatic, Lung                                                      1 (2%)                                             
      Mediastinum, Fibrosarcoma, Metastatic, Skin                                1 (2%)                                             
      Mediastinum, Leiomyosarcoma, Metastatic,                                                                                      
           Uterus                                      1 (2%)                                                                       
      Mediastinum, Leiomyosarcoma, Metastatic,                                                                                      
           Intestine Small, Ileum                                                             1 (2%)                                
      Mediastinum, Sarcoma, Metastatic, Bone                                                  1 (2%)                                
   Nose                                               (50)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Harderian Gland           1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (2)          (1)                       (4)                                    
      Carcinoma, Metastatic, Harderian Gland           1 (50%)                                                                      
   Harderian Gland                                    (4)          (2)          (2)          (2)                                    
      Adenoma                                          2 (50%)      1 (50%)      2 (100%)     2 (100%)                              
      Carcinoma                                        2 (50%)                                                                      
      Bilateral, Adenoma                                            1 (50%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (49)         (50)                                   
      Hemangiosarcoma                                  1 (2%)                                                                       
      Leiomyosarcoma, Metastatic, Uterus               1 (2%)                                                                       
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (2%)                                
   Urinary Bladder                                    (50)         (50)         (50)         (50)                                   
      Hemangiosarcoma                                  1 (2%)                                                                       
      Hemangiosarcoma, Metastatic, Bone Marrow                                                1 (2%)                                
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                                                              1 (2%)                                
      Sarcoma NOS, Metastatic, Uncertain Primary                                                                                    
          Site                                         1 (2%)                                                                       
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   

   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                                           1 (2%)                    1 (2%)                                
      Lymphoma Malignant                               9 (18%)      7 (14%)      7 (14%)      2 (4%)                                
____________________________________________________________________________________________________________________________________
     *   Number of animals with any tissue examined microscopically                                                                 


                                                             Page   7                                                               
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            34          28          29          21                                       
     Total Primary Neoplasms                           55          39          46          31                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 24          15          20          13                                       
     Total Benign Neoplasms                            32          20          25          14                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              20          17          17          14                                       
     Total Malignant Neoplasms                         23          19          21          17                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              8           2           9           4                                       
     Total Metastatic Neoplasm                         23           3          26          22                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms               1                                                                           
   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                                                                              
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 

  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                      9            5            4            3                                     
    Moribund Sacrifice                                 5            2            3                                                  
    Dosing Accident                                                                           1                                     
    Accidently Killed                                                                        24                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                34           43           41           22                                     
    Natural Death                                      1                         2                                                  
  Missing                                              1                                                                            

  Animals Examined Microscopically                    49           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (49)         (50)         (50)         (50)                                   
      Adenocarcinoma                                                1 (2%)                                                          
   Intestine Small, Duodenum                          (49)         (49)         (50)         (50)                                   
      Adenocarcinoma                                                1 (2%)       1 (2%)                                             
      Adenoma                                          2 (4%)                    2 (4%)       1 (2%)                                
   Intestine Small, Jejunum                           (49)         (50)         (50)         (50)                                   
      Adenocarcinoma                                   1 (2%)       1 (2%)       2 (4%)       2 (4%)                                
   Liver                                              (49)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Harderian Gland                                     1 (2%)                                             
      Carcinoma, Metastatic, Intestine Small,                                                                                       
          Duodenum                                                               1 (2%)                                             
      Hemangiosarcoma                                  1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Hepatoblastoma                                   1 (2%)                                                                       
      Hepatocellular Carcinoma                        10 (20%)      7 (14%)      7 (14%)      4 (8%)                                
      Hepatocellular Carcinoma, Multiple               3 (6%)                                                                       
      Hepatocellular Adenoma                          13 (27%)     15 (30%)     16 (32%)      6 (12%)                               
      Hepatocellular Adenoma, Multiple                 4 (8%)      12 (24%)      8 (16%)      6 (12%)                               
      Hepatocholangiocarcinoma                         1 (2%)       2 (4%)       1 (2%)                                             
      Sarcoma, Metastatic, Pancreas                                 1 (2%)                                                          
   Mesentery                                          (3)          (6)          (6)          (1)                                    
      Carcinoma, Metastatic, Intestine Small,                                                                                       
          Duodenum                                                               1 (17%)                                            
      Hemangiosarcoma                                               1 (17%)                                                         
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (17%)                                                         
      Sarcoma, Metastatic, Pancreas                                 1 (17%)                                                         
   Pancreas                                           (49)         (50)         (50)         (50)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                                                                       
      Sarcoma                                                       1 (2%)                                                          
   Salivary Glands                                    (49)         (50)         (50)         (50)                                   
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - cont                                                                                                            
   Stomach, Forestomach                               (49)         (50)         (50)         (50)                                   
      Squamous Cell Papilloma                          1 (2%)       2 (4%)       1 (2%)                                             
   Stomach, Glandular                                 (49)         (50)         (50)         (50)                                   
   Tooth                                              (6)                       (1)          (2)                                    
      Odontoma                                         1 (17%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (48)         (50)         (50)         (50)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (49)         (50)         (50)         (50)                                   
      Capsule, Adenoma                                 5 (10%)      4 (8%)       3 (6%)                                             
      Subcapsular, Adenoma                                                       1 (2%)                                             
   Adrenal Medulla                                    (49)         (50)         (50)         (50)                                   
      Pheochromocytoma Benign                                                                 1 (2%)                                
   Islets, Pancreatic                                 (49)         (50)         (50)         (50)                                   
      Adenoma                                          2 (4%)                    1 (2%)                                             
   Thyroid Gland                                      (49)         (50)         (50)         (50)                                   
      C-Cell, Carcinoma                                1 (2%)                                                                       
      Follicular Cell, Adenoma                                                   1 (2%)       1 (2%)                                
      Follicular Cell, Carcinoma                       1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (49)         (50)         (50)         (50)                                   
   Preputial Gland                                    (49)         (50)         (50)         (49)                                   
   Prostate                                           (49)         (50)         (50)         (50)                                   
      Hemangiosarcoma                                  1 (2%)                                                                       
      Sarcoma, Metastatic, Pancreas                                 1 (2%)                                                          
   Seminal Vesicle                                    (49)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Intestine Small,                                                                                       
          Duodenum                                                               1 (2%)                                             
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                                                          
      Sarcoma, Metastatic, Pancreas                                 1 (2%)                                                          
   Testes                                             (49)         (50)         (50)         (50)                                   
      Interstitial Cell, Adenoma                                    1 (2%)                                                          
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (49)         (50)         (50)         (50)                                   
   Lymph Node                                         (3)          (5)          (3)          (1)                                    
      Bronchial, Hepatocholangiocarcinoma,                                                                                          
          Metastatic, Liver                            1 (33%)                                                                      
      Mediastinal, Carcinoma, Metastatic,                                                                                           
          Intestine Small, Duodenum                                              1 (33%)                                            
      Mediastinal, Hepatocholangiocarcinoma,                                                                                        
          Metastatic, Liver                                         1 (20%)                                                         
      Pancreatic, Sarcoma, Metastatic, Pancreas                     1 (20%)                                                         
   Lymph Node, Mandibular                             (46)         (48)         (50)         (47)                                   
      Carcinoma, Metastatic, Harderian Gland                                     2 (4%)                                             
   Lymph Node, Mesenteric                             (46)         (43)         (49)         (47)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                                                          
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Spleen                                             (49)         (50)         (50)         (50)                                   
      Hemangiosarcoma                                  1 (2%)                                                                       
   Thymus                                             (40)         (48)         (46)         (49)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (49)         (50)         (50)         (50)                                   
      Keratoacanthoma                                  1 (2%)                                                                       
      Subcutaneous Tissue, Hemangioma                               1 (2%)                                                          
      Subcutaneous Tissue, Lipoma                      1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Skeletal Muscle                                    (1)                       (2)          (1)                                    
      Carcinoma, Metastatic, Harderian Gland                                     1 (50%)                                            
      Carcinoma, Metastatic, Intestine Small,                                                                                       
          Duodenum                                                               1 (50%)                                            
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (49)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     2 (4%)      11 (22%)      7 (14%)      4 (8%)                                
      Alveolar/Bronchiolar Adenoma, Multiple                                     1 (2%)       1 (2%)                                
      Alveolar/Bronchiolar Carcinoma                   4 (8%)       2 (4%)       1 (2%)       1 (2%)                                
      Alveolar/Bronchiolar Carcinoma, Multiple                      1 (2%)                                                          
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                     1 (2%)                                                          
      Carcinoma, Metastatic, Harderian Gland                                     2 (4%)                                             
      Carcinoma, Metastatic, Intestine Small,                                                                                       
          Duodenum                                                               1 (2%)                                             
      Hepatocellular Carcinoma, Metastatic, Liver      6 (12%)      2 (4%)       4 (8%)                                             
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)       1 (2%)       1 (2%)                                             
      Mediastinum, Carcinoma, Metastatic,                                                                                           
          Harderian Gland                                                        1 (2%)                                             
      Mediastinum, Hepatocholangiocarcinoma,                                                                                        
          Metastatic, Liver                            1 (2%)       1 (2%)                                                          
      Serosa, Hepatocholangiocarcinoma, Metastatic,                                                                                 
           Liver                                                                 1 (2%)                                             
   Nose                                               (49)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Harderian Gland                                     1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (3)          (2)          (7)          (1)                                    
      Adenoma                                          3 (100%)     2 (100%)     5 (71%)      1 (100%)                              
      Carcinoma                                                                  2 (29%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (49)         (50)         (50)         (50)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)       1 (2%)                                                          
      Renal Tubule, Adenoma                                                                   1 (2%)                                
      Renal Tubule, Carcinoma                                       1 (2%)                                                          
   Urinary Bladder                                    (49)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   

   Multiple Organs                                   *(49)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
      Lymphoma Malignant                               2 (4%)       3 (6%)       3 (6%)       1 (2%)                                
____________________________________________________________________________________________________________________________________


                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 


                                                             Page  12                                                               
NTP Experiment-Test: 88050-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/19/99  
Route: GAVAGE                                                                                                     Time: 12:44:20  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 MG/KG      1.5          3 MG/KG      6 MG/KG                                   
                                                                MG/KG                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            40          41          39          24                                       
     Total Primary Neoplasms                           62          72          64          31                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 29          35          33          19                                       
     Total Benign Neoplasms                            35          49          46          22                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              24          17          16           8                                       
     Total Malignant Neoplasms                         27          23          18           9                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              7           5           8                                                   
     Total Metastatic Neoplasm                         12          17          20                                                   
                                                                                                                                    
   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                                                                              
                             ------------------------------------------------------------                                           
                             ----------              END OF REPORT             ----------                                           
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