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TDMS Study 88050-05 Pathology Tables

NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00
Route: GAVAGE                                                                                                     Time: 14:18:54

                                                  FINAL#1 2 YEAR CHRONIC RATS




       Facility:  Battelle Columbus Laboratory

       Chemical CAS #:  126-98-7

       Lock Date:  05/05/99

       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: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 

  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 4           10            9            7                                     
    Natural Death                                      7            6            6            7                                     
    Dosing Accident                                    1            1            1                                                  
  Survivors                                                                                                                         
    Terminal Sacrifice                                38           33           34           35                                     
    Natural Death                                                                             1                                     

  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (50)         (50)         (50)         (50)                                   
      Periesophageal Tissue, Lipoma                                                           1 (2%)                                
   Intestine Large, Colon                             (50)         (50)         (50)         (50)                                   
      Polyp Adenomatous                                             1 (2%)                    1 (2%)                                
   Intestine Small, Duodenum                          (50)         (50)         (50)         (50)                                   
   Intestine Small, Ileum                             (50)         (50)         (50)         (50)                                   
   Liver                                              (50)         (49)         (48)         (50)                                   
      Hepatocellular Adenoma                           1 (2%)                                                                       
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Mesentery                                          (7)          (2)          (8)          (4)                                    
      Lipoma                                                                                  1 (25%)                               
      Fat, Histiocytic Sarcoma                                                   1 (13%)                                            
   Pancreas                                           (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
   Stomach, Glandular                                 (50)         (50)         (50)         (50)                                   
      Adenoma                                                       1 (2%)                                                          
   Tongue                                                                                    (1)                                    
      Squamous Cell Papilloma                                                                 1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (49)         (50)         (50)         (50)                                   
   Heart                                              (50)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Adenoma                                          1 (2%)                                                                       
   Adrenal Medulla                                    (50)         (50)         (50)         (50)                                   
      Pheochromocytoma Benign                          1 (2%)       3 (6%)       2 (4%)       1 (2%)                                
   Islets, Pancreatic                                 (50)         (50)         (50)         (50)                                   
      Adenoma                                                       1 (2%)       1 (2%)                                             
   Parathyroid Gland                                  (48)         (47)         (46)         (47)                                   
      Adenoma                                          1 (2%)                                                                       
   Pituitary Gland                                    (50)         (50)         (50)         (50)                                   
      Adenoma                                         12 (24%)     14 (28%)     19 (38%)     14 (28%)                               
      Carcinoma                                        1 (2%)                                                                       
      Pars Intermedia, Adenoma                                                                1 (2%)                                
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Bilateral, C-Cell, Adenoma                                                              1 (2%)                                
      C-Cell, Adenoma                                  3 (6%)       8 (16%)      5 (10%)      7 (14%)                               
      C-Cell, Carcinoma                                2 (4%)       1 (2%)       1 (2%)                                             
      Follicular Cell, Carcinoma                       1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (49)         (48)         (50)         (48)                                   
      Adenoma                                          2 (4%)                                                                       
      Carcinoma                                        1 (2%)       2 (4%)       1 (2%)                                             
      Hemangiosarcoma                                  1 (2%)                                                                       
   Ovary                                              (50)         (50)         (50)         (50)                                   
      Granulosa Cell Tumor Malignant                   1 (2%)                                                                       
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Uterus                                             (50)         (50)         (50)         (50)                                   
      Adenoma                                                                                 1 (2%)                                
      Carcinoma                                                     1 (2%)                                                          
      Deciduoma Benign                                                                        1 (2%)                                
      Leiomyosarcoma                                                                          1 (2%)                                
      Polyp Stromal                                    6 (12%)      8 (16%)      9 (18%)      8 (16%)                               
      Polyp Stromal, Multiple                                                                 3 (6%)                                
      Sarcoma Stromal                                                            1 (2%)       2 (4%)                                
      Cervix, Polyp Stromal                            1 (2%)                                                                       
      Cervix, Sarcoma Stromal                                       1 (2%)                                                          
   Vagina                                                                                    (2)                                    
      Leiomyoma                                                                               1 (50%)                               
      Sarcoma Stromal                                                                         1 (50%)                               
NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Lymph Node                                         (6)          (1)          (5)          (1)                                    
   Lymph Node, Mandibular                             (50)         (49)         (50)         (50)                                   
      Carcinoma, Metastatic, Mammary Gland             1 (2%)                                                                       
   Lymph Node, Mesenteric                             (50)         (50)         (50)         (50)                                   
   Spleen                                             (50)         (50)         (50)         (50)                                   
   Thymus                                             (48)         (49)         (47)         (47)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (50)         (50)         (50)                                   
      Adenoma                                          1 (2%)                                                                       
      Carcinoma                                        3 (6%)       1 (2%)       1 (2%)       1 (2%)                                
      Fibroadenoma                                    16 (32%)     17 (34%)     10 (20%)     16 (32%)                               
      Fibroadenoma, Multiple                           5 (10%)      9 (18%)      9 (18%)      2 (4%)                                
   Skin                                               (50)         (50)         (50)         (50)                                   
      Basal Cell Adenoma                               1 (2%)       1 (2%)                                                          
      Squamous Cell Papilloma                          1 (2%)                                                                       
      Subcutaneous Tissue, Fibroma                                                            2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Pituitary Gland           1 (2%)                                                                       
      Glioma Malignant                                                           1 (2%)                                             
      Oligodendroglioma Benign                         1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                                                            2 (4%)                                
      Carcinoma, Metastatic, Mammary Gland             1 (2%)                    1 (2%)                                             
      Carcinoma, Metastatic, Thyroid Gland             2 (4%)                                                                       
      Histiocytic Sarcoma                                                        1 (2%)                                             
      Nephroblastoma, Metastatic, Kidney                                                      1 (2%)                                
NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Zymbal's Gland                                                               (1)                                                 
      Adenoma                                                                    1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Nephroblastoma                                                                          1 (2%)                                
   Urinary Bladder                                    (50)         (50)         (50)         (50)                                   
      Transitional Epithelium, Papilloma                                         1 (2%)                                             
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   

   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
      Leukemia Mononuclear                            21 (42%)     19 (38%)     16 (32%)     19 (38%)                               
____________________________________________________________________________________________________________________________________
     *   Number of animals with any tissue examined microscopically                                                                 


                                                             Page   5                                                               
NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            45          45          42          46                                       
     Total Primary Neoplasms                           84          88          79          89                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 35          38          34          37                                       
     Total Benign Neoplasms                            53          63          57          64                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              26          21          21          24                                       
     Total Malignant Neoplasms                         31          25          22          25                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              5                       1           1                                       
     Total Metastatic Neoplasm                          5                       1           1                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    

____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
b  Primary tumors: all tumors except metastatic tumors                                                                              
NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 

  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                     12            3            6            6                                     
    Moribund Sacrifice                                13           13            9           12                                     
    Dosing Accident                                                                           1                                     
  Survivors                                                                                                                         
    Natural Death                                                                1                                                  
    Terminal Sacrifice                                25           34           34           31                                     

  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (50)         (50)         (50)         (50)                                   
      Polyp Adenomatous                                1 (2%)                    1 (2%)                                             
   Intestine Large, Rectum                            (50)         (50)         (50)         (50)                                   
      Polyp Adenomatous                                             1 (2%)                    1 (2%)                                
   Intestine Small, Duodenum                          (50)         (50)         (50)         (50)                                   
      Polyp Adenomatous                                             1 (2%)                                                          
   Intestine Small, Jejunum                           (50)         (50)         (50)         (50)                                   
      Polyp Adenomatous                                                          1 (2%)                                             
   Liver                                              (50)         (50)         (50)         (49)                                   
      Hepatocellular Adenoma                           1 (2%)       2 (4%)                                                          
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Mesentery                                          (13)         (13)         (11)         (12)                                   
      Fat, Sarcoma                                     1 (8%)                                                                       
      Fat, Schwannoma Malignant                                                               1 (8%)                                
   Pancreas                                           (50)         (49)         (50)         (50)                                   
      Adenoma                                          2 (4%)                    1 (2%)       2 (4%)                                
      Mixed Tumor Benign                                                         1 (2%)                                             
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
      Neural Crest Tumor                                                                      1 (2%)                                
      Schwannoma Malignant                             2 (4%)                    1 (2%)       1 (2%)                                
   Stomach, Forestomach                               (50)         (50)         (50)         (50)                                   
      Squamous Cell Papilloma                                                                 1 (2%)                                
   Stomach, Glandular                                 (50)         (50)         (50)         (50)                                   
      Carcinoma                                        1 (2%)                                                                       
   Tongue                                                                                    (1)                                    
      Squamous Cell Papilloma                                                                 1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Osteosarcoma, Metastatic, Bone                                1 (2%)                                                          
      Schwannoma Malignant                                                                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Adenoma                                          1 (2%)       2 (4%)                                                          
      Osteosarcoma, Metastatic, Bone                                1 (2%)                                                          
   Adrenal Medulla                                    (50)         (50)         (50)         (50)                                   
      Osteosarcoma, Metastatic, Bone                                1 (2%)                                                          
      Pheochromocytoma Malignant                       1 (2%)       1 (2%)       2 (4%)                                             
      Pheochromocytoma Benign                          2 (4%)       6 (12%)      6 (12%)      2 (4%)                                
      Bilateral, Pheochromocytoma Benign               1 (2%)       1 (2%)                                                          
   Islets, Pancreatic                                 (50)         (50)         (50)         (50)                                   
      Adenoma                                                       2 (4%)       1 (2%)       1 (2%)                                
      Carcinoma                                                     2 (4%)                                                          
   Parathyroid Gland                                  (46)         (46)         (50)         (50)                                   
      Adenoma                                                                    1 (2%)       1 (2%)                                
   Pituitary Gland                                    (50)         (50)         (50)         (50)                                   
      Adenoma                                         17 (34%)     18 (36%)     11 (22%)     20 (40%)                               
      Craniopharyngioma                                                                       1 (2%)                                
      Osteosarcoma, Metastatic, Bone                                1 (2%)                                                          
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Schwannoma Malignant, Metastatic, Skin           1 (2%)                                                                       
      Bilateral, C-Cell, Adenoma                       1 (2%)       2 (4%)       1 (2%)                                             
      C-Cell, Adenoma                                  8 (16%)     10 (20%)      7 (14%)      6 (12%)                               
      C-Cell, Carcinoma                                1 (2%)       1 (2%)       1 (2%)                                             
      Follicular Cell, Adenoma                         1 (2%)                    2 (4%)                                             
      Follicular Cell, Carcinoma                                    1 (2%)       1 (2%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Tissue NOS                                                      (1)          (1)                                                 
      Chemodectoma Benign                                                        1 (100%)                                           
      Osteosarcoma, Metastatic, Bone                                1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (50)         (50)         (50)                                   
   Preputial Gland                                    (50)         (50)         (50)         (49)                                   
      Adenoma                                          2 (4%)       1 (2%)       4 (8%)       4 (8%)                                
      Carcinoma                                        1 (2%)       1 (2%)       3 (6%)       2 (4%)                                
   Prostate                                           (50)         (50)         (50)         (50)                                   
      Adenoma                                          1 (2%)                                 1 (2%)                                
   Seminal Vesicle                                    (50)         (50)         (50)         (50)                                   
   Testes                                             (50)         (50)         (50)         (50)                                   
      Hemangiosarcoma                                                                         1 (2%)                                
      Bilateral, Interstitial Cell, Adenoma           34 (68%)     40 (80%)     43 (86%)     45 (90%)                               
      Interstitial Cell, Adenoma                       6 (12%)      5 (10%)      4 (8%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Lymph Node                                         (7)          (3)          (3)          (4)                                    
      Osteosarcoma, Metastatic, Bone                                1 (33%)                                                         
      Inguinal, Fibrosarcoma, Metastatic, Skin                                                1 (25%)                               
      Mediastinal, Histiocytic Sarcoma                                                        1 (25%)                               
   Lymph Node, Mandibular                             (49)         (50)         (49)         (49)                                   
      Neural Crest Tumor, Metastatic, Lymph Node,                                                                                   
           Mandibular                                                                         1 (2%)                                
   Lymph Node, Mesenteric                             (50)         (50)         (50)         (50)                                   
      Carcinoma                                        1 (2%)                                                                       
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Spleen                                             (50)         (50)         (50)         (49)                                   
      Hemangiosarcoma                                               1 (2%)       1 (2%)                                             
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Leiomyoma                                                     1 (2%)                                                          
   Thymus                                             (49)         (47)         (45)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (46)         (50)         (49)         (49)                                   
      Fibroadenoma                                     2 (4%)       6 (12%)      2 (4%)       8 (16%)                               
      Fibroadenoma, Multiple                                        1 (2%)                                                          
   Skin                                               (49)         (50)         (50)         (50)                                   
      Basal Cell Adenoma                                                         1 (2%)                                             
      Basal Cell Carcinoma                                                       1 (2%)                                             
      Carcinoma, Metastatic, Nose                                                             1 (2%)                                
      Hemangiosarcoma                                               1 (2%)                                                          
      Keratoacanthoma                                               4 (8%)       3 (6%)       2 (4%)                                
      Keratoacanthoma, Multiple                        1 (2%)       1 (2%)                                                          
NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
INTEGUMENTARY SYSTEM - cont                                                                                                         
      Sarcoma                                                       1 (2%)                                                          
      Squamous Cell Carcinoma                          1 (2%)                                                                       
      Subcutaneous Tissue, Fibroma                     3 (6%)       3 (6%)       2 (4%)       5 (10%)                               
      Subcutaneous Tissue, Fibroma, Multiple                        1 (2%)                                                          
      Subcutaneous Tissue, Fibrosarcoma                                          1 (2%)       2 (4%)                                
      Subcutaneous Tissue, Fibrous Histiocytoma                                               1 (2%)                                
      Subcutaneous Tissue, Lipoma                      1 (2%)                    1 (2%)                                             
      Subcutaneous Tissue, Neural Crest Tumor,                                                                                      
           Metastatic, Skin                                                                   1 (2%)                                
      Subcutaneous Tissue, Schwannoma Malignant,                                                                                    
           Metastatic, Salivary Glands                 2 (4%)                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Osteoma                                                       1 (2%)                                                          
      Cranium, Osteosarcoma                            1 (2%)                                                                       
      Vertebra, Osteosarcoma                                        1 (2%)                                                          
   Skeletal Muscle                                    (1)          (1)                                                              
      Rhabdomyosarcoma                                 1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Astrocytoma Malignant                                                      1 (2%)                                             
      Carcinoma, Metastatic, Zymbal's Gland                         1 (2%)                                                          
      Oligodendroglioma Malignant                                   1 (2%)                                                          
      Meninges, Osteosarcoma, Metastatic, Bone         1 (2%)                                                                       
   Spinal Cord                                        (1)          (2)          (1)          (1)                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                                  3 (6%)       1 (2%)       1 (2%)                                
      Alveolar/Bronchiolar Carcinoma                                             1 (2%)                                             
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Osteosarcoma, Metastatic, Bone                                1 (2%)                                                          
      Pheochromocytoma Malignant, Metastatic,                                                                                       
          Adrenal Medulla                                                        1 (2%)                                             
      Schwannoma Malignant, Metastatic, Skin           1 (2%)                                                                       
      Mediastinum, Osteosarcoma, Metastatic, Bone                   1 (2%)                                                          
   Nose                                               (50)         (50)         (49)         (50)                                   
      Osteosarcoma, Metastatic, Bone                                1 (2%)                                                          
      Respiratory Epithelium, Squamous Cell                                                                                         
NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - cont                                                                                                           
          Carcinoma                                                                           1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Zymbal's Gland                                                  (2)                       (1)                                    
      Adenoma                                                       1 (50%)                                                         
      Carcinoma                                                     1 (50%)                   1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Renal Tubule, Adenoma                                         1 (2%)                    1 (2%)                                
   Urinary Bladder                                    (50)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   

   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Leukemia Mononuclear                            20 (40%)     20 (40%)     14 (28%)     12 (24%)                               
      Mesothelioma Malignant                                                     2 (4%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
     *   Number of animals with any tissue examined microscopically                                                                 


                                                             Page  11                                                               
NTP Experiment-Test: 88050-05  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 02/24/00  
Route: GAVAGE                                                                                                     Time: 14:18:54  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 MG/KG      3 MG/KG      10 MG/KG     30 MG/KG                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            49          50          49          49                                       
     Total Primary Neoplasms                          116         146         124         133                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 47          49          49          47                                       
     Total Benign Neoplasms                            85         114          95         104                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              29          30          24          26                                       
     Total Malignant Neoplasms                         31          32          29          28                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              3           2           1           4                                       
     Total Metastatic Neoplasm                          5          10           1           5                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                      1                                       
     Total Uncertain Neoplasms                                                              1                                       
                                                                                                                                    

____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
b  Primary tumors: all tumors except metastatic tumors                                                                              
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                             ----------              END OF REPORT             ----------                                           
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