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TDMS Study 05158-04 Pathology Tables

NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24




       Facility:  Battelle Northwest

       Chemical CAS #:  1313-27-5

       Lock Date:  07/13/93

       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: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 

  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                17           12           14           10                                     
    Natural Death                                      8            6            2            5                                     
    Accidently Killed                                               1            1                                                  
  Survivors                                                                                                                         
    Terminal Sacrifice                                24           31           31           35                                     
    Moribund Sacrifice                                 1                         2                                                  

  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (40)         (44)         (46)         (41)                                   
      Carcinoma, Metastatic, Pancreas                                            1 (2%)                                             
   Intestine Small, Duodenum                          (43)         (46)         (47)         (46)                                   
      Polyp Adenomatous                                1 (2%)                                                                       
   Intestine Small, Jejunum                           (44)         (45)         (47)         (46)                                   
   Liver                                              (50)         (50)         (50)         (49)                                   
      Carcinoma, Metastatic, Islets, Pancreatic                                               1 (2%)                                
      Hemangiosarcoma                                                                         2 (4%)                                
      Hepatocellular Carcinoma                        17 (34%)      8 (16%)     13 (26%)      5 (10%)                               
      Hepatocellular Carcinoma, Multiple               2 (4%)       4 (8%)       3 (6%)       6 (12%)                               
      Hepatocellular Adenoma                           7 (14%)      8 (16%)      7 (14%)     10 (20%)                               
      Hepatocellular Adenoma, Multiple                 2 (4%)       3 (6%)       6 (12%)      6 (12%)                               
      Hepatocholangiocarcinoma                         1 (2%)                                                                       
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                    1 (2%)                                
      Teratoma Malignant, Metastatic, Ovary                         1 (2%)                                                          
   Mesentery                                          (4)          (9)          (9)          (7)                                    
      Carcinoma, Metastatic, Pancreas                                            1 (11%)                                            
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (25%)                                                                      
      Teratoma Malignant, Metastatic, Ovary                         1 (11%)                                                         
   Oral Mucosa                                        (1)          (1)                                                              
      Squamous Cell Carcinoma                                       1 (100%)                                                        
   Pancreas                                           (50)         (49)         (48)         (46)                                   
      Carcinoma                                                                  1 (2%)                                             
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                                                                       
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Salivary Glands                                    (50)         (49)         (49)         (49)                                   
   Stomach, Forestomach                               (50)         (50)         (49)         (47)                                   
      Squamous Cell Papilloma                                                    2 (4%)                                             
   Stomach, Glandular                                 (49)         (49)         (47)         (46)                                   
   Tooth                                              (2)                                                                           
      Odontoma                                         1 (50%)                                                                      

                                                             Page   2                                                               
NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (49)         (49)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                                                                       
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Pheochromocytoma Malignant, Metastatic,                                                                                       
          Adrenal Medulla                                                        1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (49)         (49)                                   
      Adenoma                                          1 (2%)       1 (2%)                                                          
      Carcinoma, Metastatic, Pancreas                                            1 (2%)                                             
      Histiocytic Sarcoma                                           1 (2%)                                                          
      Capsule, Adenoma                                                           1 (2%)                                             
   Adrenal Medulla                                    (50)         (49)         (49)         (49)                                   
      Pheochromocytoma Malignant                                                 1 (2%)                                             
      Pheochromocytoma Benign                          1 (2%)                                                                       
   Islets, Pancreatic                                 (50)         (49)         (48)         (46)                                   
      Adenoma                                          1 (2%)                                 1 (2%)                                
      Carcinoma                                                                  1 (2%)       1 (2%)                                
   Pituitary Gland                                    (49)         (48)         (48)         (49)                                   
      Pars Distalis, Adenoma                           9 (18%)      8 (17%)      9 (19%)      9 (18%)                               
      Pars Distalis, Carcinoma                                                   1 (2%)                                             
      Pars Intermedia, Adenoma                                                                2 (4%)                                
   Thyroid Gland                                      (50)         (50)         (49)         (49)                                   
      Follicular Cell, Adenoma                         2 (4%)       1 (2%)       1 (2%)       1 (2%)                                
      Follicular Cell, Adenoma, Multiple                            1 (2%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Ovary                                              (50)         (49)         (48)         (46)                                   
      Cystadenoma                                      1 (2%)       2 (4%)       3 (6%)                                             
      Granulosa Cell Tumor Benign                                   1 (2%)       1 (2%)                                             
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Luteoma                                          1 (2%)       1 (2%)       1 (2%)                                             
      Teratoma Malignant                                            1 (2%)                                                          
   Uterus                                             (50)         (50)         (49)         (49)                                   
      Carcinoma                                                                  1 (2%)                                             

                                                             Page   3                                                               
NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - cont                                                                                                               
      Hemangioma                                                                 1 (2%)                                             
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Polyp Stromal                                    4 (8%)       3 (6%)                    3 (6%)                                
      Sarcoma                                                                    1 (2%)                                             
      Endometrium, Adenoma                                                                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (49)         (49)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Lymph Node                                         (4)          (6)          (7)          (4)                                    
      Iliac, Teratoma Malignant, Metastatic, Ovary                  1 (17%)                                                         
      Pancreatic, Teratoma Malignant, Metastatic,                                                                                   
           Ovary                                                    1 (17%)                                                         
   Lymph Node, Bronchial                              (41)         (32)         (36)         (31)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                                                                       
   Lymph Node, Mandibular                             (39)         (40)         (43)         (40)                                   
      Histiocytic Sarcoma                              1 (3%)                                                                       
   Lymph Node, Mesenteric                             (49)         (49)         (46)         (44)                                   
      Carcinoma, Metastatic, Pancreas                                            1 (2%)                                             
      Histiocytic Sarcoma                              1 (2%)                                 1 (2%)                                
      Teratoma Malignant, Metastatic, Ovary                         1 (2%)                                                          
   Lymph Node, Mediastinal                            (41)         (41)         (40)         (41)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                                                                       
      Histiocytic Sarcoma                              1 (2%)                                 1 (2%)                                
   Spleen                                             (50)         (50)         (49)         (47)                                   
      Hemangiosarcoma                                               1 (2%)                                                          
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                    1 (2%)                                
   Thymus                                             (40)         (35)         (40)         (37)                                   
      Histiocytic Sarcoma                                           1 (3%)                    1 (3%)                                
      Thymoma Malignant                                             1 (3%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (49)         (49)         (49)         (50)                                   
      Carcinoma                                                     2 (4%)       1 (2%)                                             
   Skin                                               (50)         (50)         (49)         (50)                                   
      Melanoma Malignant                                            1 (2%)                                                          
      Trichoepithelioma                                             1 (2%)                                                          
      Pinna, Squamous Cell Papilloma                   1 (2%)                                                                       
      Subcutaneous Tissue, Hemangiosarcoma                                                    1 (2%)                                
      Subcutaneous Tissue, Osteosarcoma                1 (2%)                                                                       
      Subcutaneous Tissue, Sarcoma                                  1 (2%)       2 (4%)       4 (8%)                                
      Subcutaneous Tissue, Sarcoma, Multiple                                     1 (2%)                                             
____________________________________________________________________________________________________________________________________

                                                             Page   4                                                               
NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Osteosarcoma                                     1 (2%)                                                                       
   Skeletal Muscle                                    (1)          (1)                                                              
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (100%)                                                                     
      Teratoma Malignant, Metastatic, Ovary                         1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (49)         (49)                                   
      Carcinoma, Metastatic, Pituitary Gland                                     1 (2%)                                             
      Histiocytic Sarcoma                              1 (2%)                                 1 (2%)                                
      Choroid Plexus, Adenoma                                                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (49)         (49)                                   
      Alveolar/Bronchiolar Adenoma                     1 (2%)       4 (8%)       8 (16%)      8 (16%)                               
      Alveolar/Bronchiolar Adenoma, Multiple                                                  1 (2%)                                
      Alveolar/Bronchiolar Carcinoma                   2 (4%)       2 (4%)                    6 (12%)                               
      Carcinoma, Metastatic, Harderian Gland           1 (2%)                                 1 (2%)                                
      Hepatocellular Carcinoma, Metastatic, Liver      2 (4%)       3 (6%)       2 (4%)       1 (2%)                                
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                                                                       
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                    1 (2%)                                
      Pheochromocytoma Malignant, Metastatic,                                                                                       
          Adrenal Medulla                                                        1 (2%)                                             
      Teratoma Malignant, Metastatic, Ovary                         1 (2%)                                                          
   Nose                                               (49)         (50)         (49)         (49)                                   
      Carcinoma, Metastatic, Harderian Gland                                                  1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (3)          (2)          (1)          (1)                                    
      Adenoma                                          2 (67%)      2 (100%)                                                        
      Carcinoma                                        1 (33%)                   1 (100%)     1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (49)         (47)                                   
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                    1 (2%)                                
      Teratoma Malignant, Metastatic, Ovary                         1 (2%)                                                          
      Renal Tubule, Carcinoma                          1 (2%)                                                                       

                                                             Page   5                                                               
NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - cont                                                                                                               
   Urinary Bladder                                    (48)         (50)         (49)         (46)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   

   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                    1 (2%)                                
      Lymphoma Malignant                               3 (6%)       5 (10%)      8 (16%)      6 (12%)                               
____________________________________________________________________________________________________________________________________

                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 

                                                             Page   6                                                               
NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            40          39          43          40                                       
     Total Primary Neoplasms                           65          64          75          77                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 25          24          30          26                                       
     Total Benign Neoplasms                            35          36          40          44                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              28          25          29          25                                       
     Total Malignant Neoplasms                         30          28          35          33                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              4           4           5           3                                       
     Total Metastatic Neoplasm                         10          11           9           4                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    

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

                                                             Page   7                                                               
NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 

  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                      6            4           11            4                                     
    Moribund Sacrifice                                 8           13           14            9                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                36           33           25           37                                     

  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (43)         (40)         (38)         (43)                                   
   Intestine Small, Duodenum                          (44)         (47)         (41)         (48)                                   
      Sarcoma                                                                    1 (2%)                                             
   Intestine Small, Jejunum                           (44)         (46)         (41)         (48)                                   
      Hemangiosarcoma                                                            1 (2%)                                             
   Intestine Small, Ileum                             (44)         (46)         (41)         (48)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Liver                                              (50)         (50)         (50)         (50)                                   
      Hemangiosarcoma                                                            1 (2%)                                             
      Hepatocellular Carcinoma                         9 (18%)      7 (14%)     13 (26%)     10 (20%)                               
      Hepatocellular Carcinoma, Multiple               3 (6%)      11 (22%)      8 (16%)      3 (6%)                                
      Hepatocellular Adenoma                          13 (26%)     12 (24%)     15 (30%)     14 (28%)                               
      Hepatocellular Adenoma, Multiple                 7 (14%)      3 (6%)       4 (8%)       5 (10%)                               
      Hepatocholangiocarcinoma                                                   1 (2%)                                             
      Histiocytic Sarcoma                                           1 (2%)                                                          
      Sarcoma                                                                                 1 (2%)                                
   Mesentery                                          (3)          (4)          (2)          (2)                                    
   Pancreas                                           (50)         (48)         (48)         (50)                                   
   Salivary Glands                                    (50)         (50)         (49)         (50)                                   
   Stomach, Forestomach                               (50)         (49)         (48)         (50)                                   
      Squamous Cell Papilloma                                                                 1 (2%)                                
   Stomach, Glandular                                 (50)         (48)         (46)         (49)                                   
      Carcinoma                                        1 (2%)                                                                       
   Tooth                                                           (1)          (1)          (1)                                    
      Odontoma                                                      1 (100%)     1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    

                                                             Page   8                                                               
NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (49)         (48)         (50)                                   
      Adenoma                                          1 (2%)       1 (2%)       2 (4%)                                             
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                        1 (2%)                                                                       
   Adrenal Medulla                                    (50)         (49)         (48)         (50)                                   
      Pheochromocytoma Benign                                                    1 (2%)                                             
   Islets, Pancreatic                                 (50)         (48)         (48)         (50)                                   
      Adenoma                                                       2 (4%)                    1 (2%)                                
      Carcinoma                                                     1 (2%)                                                          
   Pituitary Gland                                    (47)         (47)         (46)         (47)                                   
      Pars Intermedia, Adenoma                                      1 (2%)                    2 (4%)                                
   Thyroid Gland                                      (50)         (50)         (49)         (50)                                   
      Follicular Cell, Adenoma                         1 (2%)       3 (6%)       2 (4%)       1 (2%)                                
      Follicular Cell, Carcinoma                       1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (50)         (49)         (50)                                   
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                                                          
   Preputial Gland                                    (49)         (50)         (48)         (50)                                   
      Histiocytic Sarcoma                                                                     1 (2%)                                
   Prostate                                           (48)         (47)         (47)         (47)                                   
   Seminal Vesicle                                    (50)         (48)         (47)         (49)                                   
   Testes                                             (50)         (50)         (49)         (50)                                   
      Hemangioma                                                                 1 (2%)                                             
      Bilateral, Interstitial Cell, Adenoma                                      1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (49)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
      Mast Cell Tumor Malignant                                                               1 (2%)                                
   Lymph Node                                         (2)          (3)          (2)          (2)                                    
      Renal, Histiocytic Sarcoma                       1 (50%)      1 (33%)                                                         
   Lymph Node, Bronchial                              (31)         (37)         (32)         (36)                                   
      Histiocytic Sarcoma                                           1 (3%)                                                          
   Lymph Node, Mandibular                             (32)         (33)         (32)         (34)                                   
   Lymph Node, Mesenteric                             (46)         (47)         (45)         (48)                                   
      Histiocytic Sarcoma                              1 (2%)       2 (4%)                                                          

                                                             Page   9                                                               
NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
   Lymph Node, Mediastinal                            (34)         (37)         (39)         (34)                                   
      Histiocytic Sarcoma                                           1 (3%)                                                          
   Spleen                                             (50)         (48)         (49)         (50)                                   
      Hemangiosarcoma                                  1 (2%)                                                                       
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                                                          
      Sarcoma                                                                                 1 (2%)                                
   Thymus                                             (30)         (35)         (32)         (36)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (50)         (49)         (50)                                   
      Squamous Cell Carcinoma                                       1 (2%)                                                          
      Subcutaneous Tissue, Sarcoma                                               1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (49)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (49)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     8 (16%)     13 (26%)     10 (20%)      8 (16%)                               
      Alveolar/Bronchiolar Adenoma, Multiple           1 (2%)       1 (2%)                    1 (2%)                                
      Alveolar/Bronchiolar Carcinoma                   1 (2%)       9 (18%)     13 (27%)      7 (14%)                               
      Alveolar/Bronchiolar Carcinoma, Multiple         1 (2%)       7 (14%)      1 (2%)       3 (6%)                                
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                  1 (2%)                                             
      Carcinoma, Metastatic, Harderian Gland                                                  1 (2%)                                
      Hepatocellular Carcinoma, Metastatic, Liver      5 (10%)      2 (4%)       6 (12%)      3 (6%)                                
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Nose                                               (50)         (50)         (49)         (50)                                   
      Carcinoma, Metastatic, Harderian Gland                                                  1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    

                                                             Page  10                                                               
NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Ear                                                             (1)                                                              
      Histiocytic Sarcoma                                           1 (100%)                                                        
   Harderian Gland                                    (3)          (4)          (4)          (3)                                    
      Adenoma                                          1 (33%)      4 (100%)     4 (100%)     2 (67%)                               
      Carcinoma                                        2 (67%)                                1 (33%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (49)         (50)         (49)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
   Urinary Bladder                                    (50)         (49)         (46)         (49)                                   
      Hemangioma                                                                              1 (2%)                                
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   

   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                              2 (4%)       4 (8%)                    1 (2%)                                
      Lymphoma Malignant                               2 (4%)       2 (4%)       2 (4%)       2 (4%)                                
____________________________________________________________________________________________________________________________________

                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 

                                                             Page  11                                                               
NTP Experiment-Test: 05158-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                        MOLYBDENUM TRIOXIDE                                    Date: 04/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 02:35:24  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      10 MG/M3     30 MG/M3     100                                       
                                                                                          MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            40          44          45          42                                       
     Total Primary Neoplasms                           55          83          83          66                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 28          26          28          28                                       
     Total Benign Neoplasms                            32          41          41          36                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              20          36          35          24                                       
     Total Malignant Neoplasms                         23          42          42          30                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              6           2           7           4                                       
     Total Metastatic Neoplasm                          6           2           7           5                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    

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

                                                             Page  12                                                               
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