National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/3171

TDMS Study 92012-06 Pathology Tables

NTP Experiment-Test: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03
Route: DOSED FEED                                                                                                 Time: 07:34:38

                                                          FINAL#1/MICE




       Facility:  Southern Research Institute

       Chemical CAS #:  693-98-1

       Lock Date:  10/16/01

       Cage Range:  All

       Reasons For Removal:    25019 Moribund Sacrifice                25020 Natural Death
                               25021 Terminal Sacrifice

       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: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03  
Route: DOSED FEED                                                                                                 Time: 07:34:38  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0PPM         625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially in Study                          60           60           60           60                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 2            3            4            4                                     
    Natural Death                                      2            3            2            1                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                46           42           42           45                                     
    Moribund Sacrifice                                                           1                                                  
    Natural Death                                                   1                                                               
                                                                                                                                    
  Animals Examined Microscopically                    50           49           49           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (50)         (48)         (48)         (50)                                   
   Intestine Small, Duodenum                          (50)         (49)         (48)         (49)                                   
      Carcinoma                                                                               1 (2%)                                
      Polyp Adenomatous                                             1 (2%)                                                          
   Intestine Small, Jejunum                           (50)         (46)         (48)         (49)                                   
      Serosa, Histiocytic Sarcoma                                                             1 (2%)                                
   Liver                                              (50)         (49)         (49)         (50)                                   
      Hepatocellular Carcinoma                         2 (4%)                                                                       
      Hepatocellular Adenoma                           2 (4%)       3 (6%)       6 (12%)      9 (18%)                               
      Hepatocellular Adenoma, Multiple                 1 (2%)       1 (2%)                    1 (2%)                                
      Histiocytic Sarcoma                                                        1 (2%)       1 (2%)                                
   Pancreas                                           (50)         (49)         (48)         (50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Salivary Glands                                    (50)         (49)         (49)         (49)                                   
   Stomach, Forestomach                               (50)         (49)         (49)         (50)                                   
      Squamous Cell Papilloma                          1 (2%)       1 (2%)                    2 (4%)                                
      Squamous Cell Papilloma, Multiple                1 (2%)                                                                       
   Stomach, Glandular                                 (50)         (49)         (48)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (49)         (49)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   2                                                               
                                                                                                                                   
NTP Experiment-Test: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03  
Route: DOSED FEED                                                                                                 Time: 07:34:38  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0PPM         625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Medulla                                    (50)         (49)         (49)         (50)                                   
      Pheochromocytoma Malignant                                                 1 (2%)                                             
   Islets, Pancreatic                                 (50)         (48)         (48)         (50)                                   
      Adenoma                                                       1 (2%)                                                          
   Pituitary Gland                                    (50)         (49)         (47)         (49)                                   
      Pars Distalis, Adenoma                           1 (2%)       1 (2%)                                                          
   Thyroid Gland                                      (49)         (48)         (48)         (50)                                   
      Unilateral, Follicular Cell, Adenoma             1 (2%)                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Ovary                                              (50)         (49)         (49)         (48)                                   
      Cystadenoma                                                   1 (2%)                                                          
      Granulosa-Theca Tumor Benign                                  1 (2%)                                                          
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Luteoma                                                                    1 (2%)       1 (2%)                                
   Uterus                                             (50)         (49)         (49)         (50)                                   
      Hemangiosarcoma                                  1 (2%)                                                                       
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Polyp Stromal                                                              2 (4%)                                             
      Sarcoma Stromal                                  1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (49)         (48)         (50)                                   
      Hemangiosarcoma                                               1 (2%)                                                          
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Lymph Node                                         (12)         (6)          (8)          (9)                                    
   Lymph Node, Mandibular                             (48)         (48)         (46)         (48)                                   
   Lymph Node, Mesenteric                             (48)         (48)         (47)         (48)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Spleen                                             (50)         (49)         (49)         (50)                                   
      Hemangiosarcoma                                               1 (2%)                                                          
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Thymus                                             (50)         (48)         (48)         (50)                                   
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   3                                                               
                                                                                                                                   
NTP Experiment-Test: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03  
Route: DOSED FEED                                                                                                 Time: 07:34:38  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0PPM         625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (49)         (49)         (49)         (50)                                   
      Carcinoma                                        1 (2%)                                 2 (4%)                                
   Skin                                               (50)         (49)         (49)         (50)                                   
      Basal Cell Carcinoma                                                       1 (2%)                                             
      Keratoacanthoma                                               1 (2%)                                                          
      Subcutaneous Tissue, Fibrosarcoma                                          3 (6%)       1 (2%)                                
      Subcutaneous Tissue, Fibrous Histiocytoma                                  1 (2%)                                             
      Subcutaneous Tissue, Hemangiosarcoma             1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (49)         (49)         (50)                                   
      Osteoma                                                                                 1 (2%)                                
      Osteosarcoma                                     1 (2%)                                                                       
   Skeletal Muscle                                                 (1)          (1)                                                 
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (49)         (49)         (50)                                   
      Cranial Nerve, Schwannoma Malignant                                        1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (49)         (49)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     4 (8%)       2 (4%)                    1 (2%)                                
      Alveolar/Bronchiolar Carcinoma                                2 (4%)                                                          
      Histiocytic Sarcoma                                                        1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (50)         (49)         (49)         (50)                                   
      Adenoma                                          3 (6%)       2 (4%)       6 (12%)      6 (12%)                               
      Carcinoma                                        1 (2%)                    1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   4                                                               
                                                                                                                                   
NTP Experiment-Test: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03  
Route: DOSED FEED                                                                                                 Time: 07:34:38  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0PPM         625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (49)         (49)         (50)                                   
   Urinary Bladder                                    (50)         (49)         (49)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
                                                                                                                                    
   Multiple Organs                                   *(50)        *(49)        *(49)        *(50)                                   
      Histiocytic Sarcoma                                                        1 (2%)       1 (2%)                                
      Lymphoma Malignant                               6 (12%)      8 (16%)      6 (12%)      8 (16%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   5                                                               
                                                                                                                                   
NTP Experiment-Test: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03  
Route: DOSED FEED                                                                                                 Time: 07:34:38  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0PPM         625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            23          20          23          29                                       
     Total Primary Neoplasms                           28          28          30          36                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 13          12          14          20                                       
     Total Benign Neoplasms                            14          15          15          22                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              12          12          15          14                                       
     Total Malignant Neoplasms                         14          13          15          14                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms                                                                                          
     Total Metastatic Neoplasm                                                                                                      
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
b  Primary tumors: all tumors except metastatic tumors                                                                              
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   6                                                               
                                                                                                                                   
NTP Experiment-Test: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03  
Route: DOSED FEED                                                                                                 Time: 07:34:38  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0PPM         625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially in Study                          60           60           60           60                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 4            1            5            5                                     
    Natural Death                                      3            3            9            5                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                43           46           36           40                                     
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (49)         (49)         (47)         (50)                                   
   Intestine Small, Duodenum                          (49)         (49)         (45)         (50)                                   
      Polyp Adenomatous                                1 (2%)                    1 (2%)                                             
   Intestine Small, Jejunum                           (50)         (49)         (46)         (50)                                   
      Carcinoma                                        1 (2%)       1 (2%)       1 (2%)                                             
   Liver                                              (50)         (50)         (50)         (50)                                   
      Hemangioma                                                                              1 (2%)                                
      Hemangiosarcoma                                  1 (2%)                                 2 (4%)                                
      Hepatocellular Carcinoma                         4 (8%)       5 (10%)      8 (16%)      5 (10%)                               
      Hepatocellular Carcinoma, Multiple                            3 (6%)       6 (12%)      1 (2%)                                
      Hepatocellular Adenoma                           5 (10%)     11 (22%)      9 (18%)     15 (30%)                               
      Hepatocellular Adenoma, Multiple                 2 (4%)       3 (6%)       4 (8%)       3 (6%)                                
      Histiocytic Sarcoma                              1 (2%)                    1 (2%)                                             
      Liposarcoma, Metastatic, Uncertain Primary                                                                                    
          Site                                                                                1 (2%)                                
      Osteosarcoma, Metastatic, Bone                                                          1 (2%)                                
   Pancreas                                           (50)         (50)         (49)         (50)                                   
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
   Stomach, Forestomach                               (50)         (49)         (50)         (50)                                   
      Squamous Cell Papilloma                                       1 (2%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Liposarcoma, Metastatic, Uncertain Primary                                                                                    
          Site                                                                                1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   7                                                               
                                                                                                                                   
NTP Experiment-Test: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03  
Route: DOSED FEED                                                                                                 Time: 07:34:38  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0PPM         625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Capsule, Adenoma                                              2 (4%)                    1 (2%)                                
   Islets, Pancreatic                                 (50)         (50)         (49)         (50)                                   
      Adenoma                                                                                 1 (2%)                                
   Pituitary Gland                                    (49)         (48)         (48)         (50)                                   
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Bilateral, Follicular Cell, Adenoma                                                     1 (2%)                                
      Follicular Cell, Adenoma                                      1 (2%)                                                          
      Unilateral, Follicular Cell, Adenoma                                                    6 (12%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (50)         (50)         (50)                                   
   Preputial Gland                                    (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Testes                                             (50)         (50)         (50)         (50)                                   
      Sertoli Cell Tumor Malignant                     1 (2%)                                                                       
      Interstitial Cell, Adenoma                                                 1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Hemangiosarcoma                                  1 (2%)       1 (2%)                                                          
      Histiocytic Sarcoma                              1 (2%)                                                                       
   Lymph Node                                         (2)          (3)                       (1)                                    
      Inguinal, Histiocytic Sarcoma                    1 (50%)                                                                      
      Inguinal, Osteosarcoma, Metastatic, Bone                                                1 (100%)                              
      Mediastinal, Osteosarcoma, Metastatic, Bone                                             1 (100%)                              
   Lymph Node, Mandibular                             (48)         (46)         (45)         (50)                                   
      Histiocytic Sarcoma                              1 (2%)                                                                       
   Lymph Node, Mesenteric                             (47)         (47)         (46)         (48)                                   
      Histiocytic Sarcoma                              1 (2%)                                                                       
   Spleen                                             (50)         (50)         (49)         (50)                                   
      Hemangiosarcoma                                  1 (2%)                    1 (2%)                                             
      Histiocytic Sarcoma                              1 (2%)                                                                       
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   8                                                               
                                                                                                                                   
NTP Experiment-Test: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03  
Route: DOSED FEED                                                                                                 Time: 07:34:38  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0PPM         625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
   Thymus                                             (47)         (46)         (46)         (47)                                   
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Osteosarcoma, Metastatic, Bone                                                          1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (50)         (50)         (50)                                   
      Subcutaneous Tissue, Fibrous Histiocytoma                     1 (2%)                                                          
      Subcutaneous Tissue, Hemangiosarcoma             1 (2%)                                                                       
      Subcutaneous Tissue, Sarcoma                     1 (2%)                                                                       
      Subcutaneous Tissue, Schwannoma Benign                                     1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Liposarcoma, Metastatic, Uncertain Primary                                                                                    
          Site                                                                                1 (2%)                                
      Osteoma                                                       1 (2%)                                                          
      Osteosarcoma                                                                            1 (2%)                                
   Skeletal Muscle                                    (1)          (1)                       (2)                                    
      Hemangiosarcoma                                               1 (100%)                                                        
      Liposarcoma, Metastatic, Uncertain Primary                                                                                    
          Site                                                                                1 (50%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                    11 (22%)      7 (14%)      6 (12%)      4 (8%)                                
      Alveolar/Bronchiolar Adenoma, Multiple                                                  1 (2%)                                
      Alveolar/Bronchiolar Carcinoma                   5 (10%)      2 (4%)       4 (8%)       4 (8%)                                
      Alveolar/Bronchiolar Carcinoma, Multiple         1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Carcinoma, Metastatic, Harderian Gland           1 (2%)                                                                       
      Carcinoma, Metastatic, Kidney                                              1 (2%)                                             
      Hemangiosarcoma, Metastatic, Liver                                                      1 (2%)                                
      Hepatocellular Carcinoma, Metastatic, Liver                   3 (6%)       6 (12%)      2 (4%)                                
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   9                                                               
                                                                                                                                   
NTP Experiment-Test: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03  
Route: DOSED FEED                                                                                                 Time: 07:34:38  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0PPM         625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - cont                                                                                                           
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Liposarcoma, Metastatic, Uncertain Primary                                                                                    
          Site                                                                                1 (2%)                                
      Osteosarcoma, Metastatic, Bone                                                          1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (50)         (50)         (48)         (50)                                   
      Adenoma                                          9 (18%)      6 (12%)      5 (10%)      3 (6%)                                
      Carcinoma                                        1 (2%)       3 (6%)       1 (2%)       2 (4%)                                
      Histiocytic Sarcoma                              1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Liposarcoma, Metastatic, Uncertain Primary                                                                                    
          Site                                                                                1 (2%)                                
      Renal Tubule, Adenoma                                                                   1 (2%)                                
      Renal Tubule, Carcinoma                          1 (2%)                    1 (2%)                                             
   Urinary Bladder                                    (50)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
                                                                                                                                    
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                              1 (2%)                    1 (2%)                                             
      Leukemia Granulocytic                                                      1 (2%)                                             
      Lymphoma Malignant                               2 (4%)       3 (6%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  10                                                               
                                                                                                                                   
NTP Experiment-Test: 92012-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                         2-METHYLIMIDAZOLE                                     Date: 02/25/03  
Route: DOSED FEED                                                                                                 Time: 07:34:38  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0PPM         625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            32          34          34          38                                       
     Total Primary Neoplasms                           50          53          52          56                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 23          25          24          30                                       
     Total Benign Neoplasms                            28          32          27          39                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              20          16          21          14                                       
     Total Malignant Neoplasms                         22          21          25          17                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              1           3           7           5                                       
     Total Metastatic Neoplasm                          1           3           7          14                                       
                                                                                                                                    
   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                                                                              
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  11                                                               
                                                                                                                                   
                             ------------------------------------------------------------                                           
                             ----------              END OF REPORT             ----------                                           
                             ------------------------------------------------------------                                           
NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.