National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/2536

TDMS Study 05156-06 Pathology Tables

NTP Experiment-Test: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43

                                                           CORE STUDY




       Facility:  Battelle Northwest

       Chemical CAS #:  10026-24-1

       Lock Date:  07/12/94

       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: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                      5            3            5            6                                     
    Moribund Sacrifice                                11           10           13           16                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                34           37           32           28                                     
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (43)         (43)         (38)         (43)                                   
   Intestine Large, Cecum                             (49)         (49)         (48)         (47)                                   
      Leiomyoma                                                                               1 (2%)                                
   Intestine Small, Duodenum                          (47)         (48)         (47)         (45)                                   
   Intestine Small, Jejunum                           (48)         (49)         (47)         (44)                                   
      Hemangiosarcoma                                                            1 (2%)                                             
   Intestine Small, Ileum                             (48)         (48)         (47)         (45)                                   
   Liver                                              (50)         (50)         (50)         (49)                                   
      Hemangiosarcoma                                  1 (2%)                    3 (6%)                                             
      Hepatocellular Carcinoma                        12 (24%)      9 (18%)     16 (32%)      4 (8%)                                
      Hepatocellular Adenoma                           7 (14%)      7 (14%)     11 (22%)      9 (18%)                               
      Hepatocellular Adenoma, Multiple                 1 (2%)       3 (6%)       2 (4%)       3 (6%)                                
      Hepatocholangiocarcinoma                         2 (4%)                                                                       
      Histiocytic Sarcoma                              3 (6%)       2 (4%)                    2 (4%)                                
   Mesentery                                          (10)         (12)         (8)          (7)                                    
      Hemangioma                                                                              1 (14%)                               
      Hemangiosarcoma                                               1 (8%)       1 (13%)                                            
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (10%)                                                                      
      Histiocytic Sarcoma                                           1 (8%)                                                          
      Sarcoma                                          1 (10%)                                                                      
   Pancreas                                           (50)         (50)         (49)         (49)                                   
      Histiocytic Sarcoma                              1 (2%)                                                                       
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
   Stomach, Forestomach                               (50)         (50)         (49)         (50)                                   
      Squamous Cell Papilloma                          1 (2%)       1 (2%)                    1 (2%)                                
   Stomach, Glandular                                 (50)         (50)         (49)         (50)                                   
      Muscularis, Serosa, Sarcoma                      1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page   2                                                               
NTP Experiment-Test: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (49)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)                                                          
      Capsule, Adenoma                                              1 (2%)                                                          
   Adrenal Medulla                                    (49)         (50)         (49)         (49)                                   
      Pheochromocytoma Benign                                       1 (2%)                                                          
   Islets, Pancreatic                                 (50)         (50)         (49)         (49)                                   
      Adenoma                                          1 (2%)                                 1 (2%)                                
   Pituitary Gland                                    (48)         (47)         (47)         (48)                                   
      Pars Distalis, Adenoma                          11 (23%)      8 (17%)      7 (15%)      8 (17%)                               
   Thyroid Gland                                      (50)         (49)         (49)         (49)                                   
      Follicular Cell, Adenoma                         3 (6%)                                 5 (10%)                               
      Follicular Cell, Carcinoma                       1 (2%)                    2 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Ovary                                              (48)         (49)         (49)         (48)                                   
      Arrhenoblastoma Benign                           1 (2%)                                                                       
      Cystadenocarcinoma                                            1 (2%)                                                          
      Cystadenoma                                      2 (4%)       3 (6%)       3 (6%)       3 (6%)                                
      Granulosa Cell Tumor Benign                      1 (2%)                    1 (2%)                                             
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                    1 (2%)                                
      Luteoma                                          1 (2%)                    1 (2%)                                             
      Teratoma Benign                                  1 (2%)       1 (2%)       1 (2%)                                             
      Yolk Sac Carcinoma                                                         1 (2%)                                             
   Uterus                                             (50)         (50)         (49)         (49)                                   
      Hemangioma                                                    1 (2%)       2 (4%)                                             
      Hemangiosarcoma                                               1 (2%)                                                          
      Histiocytic Sarcoma                              1 (2%)                                 1 (2%)                                
      Leiomyoma                                        1 (2%)                                                                       
      Leiomyosarcoma                                                                          1 (2%)                                
      Polyp Stromal                                                 2 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page   3                                                               
NTP Experiment-Test: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (49)         (50)                                   
      Histiocytic Sarcoma                              1 (2%)                                 2 (4%)                                
   Lymph Node                                         (3)          (6)          (3)          (4)                                    
      Histiocytic Sarcoma                              1 (33%)                                                                      
      Lumbar, Histiocytic Sarcoma                      1 (33%)                                                                      
      Renal, Histiocytic Sarcoma                       2 (67%)                                                                      
   Lymph Node, Bronchial                              (30)         (34)         (27)         (35)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver      2 (7%)                                                                       
      Histiocytic Sarcoma                              1 (3%)       1 (3%)                    1 (3%)                                
   Lymph Node, Mandibular                             (37)         (37)         (36)         (36)                                   
      Histiocytic Sarcoma                              2 (5%)       2 (5%)                    1 (3%)                                
   Lymph Node, Mesenteric                             (46)         (45)         (46)         (44)                                   
      Histiocytic Sarcoma                              3 (7%)       2 (4%)                    1 (2%)                                
   Lymph Node, Mediastinal                            (41)         (36)         (28)         (34)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (3%)                                
      Hepatocholangiocarcinoma, Metastatic, Liver      2 (5%)                                                                       
      Histiocytic Sarcoma                              3 (7%)       2 (6%)                    1 (3%)                                
   Spleen                                             (50)         (50)         (49)         (49)                                   
      Histiocytic Sarcoma                              3 (6%)       2 (4%)                    1 (2%)                                
   Thymus                                             (41)         (44)         (41)         (41)                                   
      Histiocytic Sarcoma                              1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (47)         (50)         (50)         (50)                                   
      Adenoma                                                                                 1 (2%)                                
      Carcinoma                                        1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
   Skin                                               (49)         (50)         (50)         (50)                                   
      Hemangiosarcoma                                                            1 (2%)                                             
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Squamous Cell Carcinoma                          1 (2%)                                                                       
      Subcutaneous Tissue, Mast Cell Tumor Benign                                1 (2%)                                             
      Subcutaneous Tissue, Sarcoma                     6 (12%)      2 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Skeletal Muscle                                                 (1)          (2)          (1)                                    
      Sarcoma                                                                    1 (50%)      1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page   4                                                               
NTP Experiment-Test: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     3 (6%)       5 (10%)      8 (16%)      8 (16%)                               
      Alveolar/Bronchiolar Adenoma, Multiple                        1 (2%)       1 (2%)       2 (4%)                                
      Alveolar/Bronchiolar Carcinoma                   1 (2%)       1 (2%)       4 (8%)       9 (18%)                               
      Hepatocellular Carcinoma, Metastatic, Liver      3 (6%)                    5 (10%)      2 (4%)                                
      Hepatocholangiocarcinoma, Metastatic, Liver      2 (4%)                                                                       
      Histiocytic Sarcoma                              3 (6%)       2 (4%)                    1 (2%)                                
      Sarcoma, Metastatic, Skin                        1 (2%)                                                                       
   Nose                                               (50)         (50)         (49)         (48)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (2)          (2)                       (1)                                    
      Adenoma                                          2 (100%)     2 (100%)                  1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                              2 (4%)       1 (2%)                    1 (2%)                                
   Urinary Bladder                                    (48)         (47)         (45)         (46)                                   
      Histiocytic Sarcoma                              1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                              3 (6%)       2 (4%)                    3 (6%)                                
      Lymphoma Malignant                               4 (8%)       7 (14%)      7 (14%)      5 (10%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                             Page   5                                                               
NTP Experiment-Test: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            42          41          43          39                                       
     Total Primary Neoplasms                           70          61          76          68                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 25          32          27          27                                       
     Total Benign Neoplasms                            36          36          38          44                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              27          22          31          21                                       
     Total Malignant Neoplasms                         34          25          38          24                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              6                       5           3                                       
     Total Metastatic Neoplasm                         12                       5           3                                       
                                                                                                                                    
   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: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                19           16           17           23                                     
    Accidently Killed                                  1                                      1                                     
    Natural Death                                      8            3            9            6                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                22           31           24           20                                     
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (45)         (49)         (45)         (46)                                   
   Intestine Small, Duodenum                          (45)         (49)         (42)         (45)                                   
      Polyp Adenomatous                                             1 (2%)                                                          
   Intestine Small, Jejunum                           (45)         (48)         (42)         (45)                                   
      Carcinoma                                                     1 (2%)                                                          
   Intestine Small, Ileum                             (45)         (49)         (43)         (44)                                   
   Liver                                              (50)         (50)         (50)         (50)                                   
      Hemangiosarcoma                                  2 (4%)       4 (8%)       8 (16%)      7 (14%)                               
      Hepatoblastoma                                   4 (8%)                    2 (4%)       2 (4%)                                
      Hepatocellular Carcinoma                        16 (32%)     32 (64%)     29 (58%)     26 (52%)                               
      Hepatocellular Carcinoma, Multiple               7 (14%)      1 (2%)       1 (2%)       4 (8%)                                
      Hepatocellular Adenoma                          14 (28%)     12 (24%)     16 (32%)      6 (12%)                               
      Hepatocellular Adenoma, Multiple                 8 (16%)      9 (18%)      9 (18%)      7 (14%)                               
      Hepatocholangiocarcinoma                         1 (2%)                                                                       
      Histiocytic Sarcoma                              1 (2%)                                 1 (2%)                                
      Sarcoma                                                                                 1 (2%)                                
   Mesentery                                          (3)          (4)          (5)          (4)                                    
      Hemangiosarcoma                                               1 (25%)                   1 (25%)                               
      Hepatocellular Carcinoma, Metastatic, Liver                                1 (20%)                                            
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (33%)                                                                      
      Sarcoma, Metastatic, Liver                                                              1 (25%)                               
   Pancreas                                           (48)         (50)         (49)         (50)                                   
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Sarcoma, Metastatic, Liver                                                              1 (2%)                                
   Stomach, Forestomach                               (49)         (50)         (50)         (50)                                   
      Sarcoma, Metastatic, Liver                                                              1 (2%)                                
      Squamous Cell Carcinoma                                       2 (4%)                                                          
      Squamous Cell Papilloma                                                    1 (2%)                                             
   Stomach, Glandular                                 (48)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Serosa, Hepatocellular Carcinoma, Metastatic,                                                                                 
           Liver                                                    1 (2%)                                                          
                                                             Page   7                                                               
NTP Experiment-Test: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (2%)                                
      Hemangiosarcoma                                               1 (2%)                                                          
      Sarcoma, Metastatic, Liver                                                              1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (49)         (50)         (49)         (50)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                                                                       
   Adrenal Medulla                                    (48)         (50)         (49)         (50)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                                                                       
      Pheochromocytoma Benign                          1 (2%)                                 1 (2%)                                
   Islets, Pancreatic                                 (48)         (50)         (49)         (50)                                   
      Adenoma                                                       1 (2%)                                                          
   Thyroid Gland                                      (49)         (50)         (50)         (50)                                   
      Follicular Cell, Adenoma                                                                1 (2%)                                
      Follicular Cell, Carcinoma                                                 1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                         (1)                                                                           
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (100%)                                                                     
   Tissue NOS                                         (1)                       (1)                                                 
      Hemangioma                                       1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (49)         (50)         (50)         (50)                                   
      Leiomyoma                                                                  1 (2%)                                             
   Testes                                             (49)         (50)         (50)         (50)                                   
      Interstitial Cell, Adenoma                                    1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (49)         (50)         (50)         (50)                                   
      Hemangiosarcoma                                               2 (4%)                    1 (2%)                                
   Lymph Node                                         (1)          (1)          (2)          (2)                                    
      Iliac, Sarcoma, Metastatic, Liver                                                       1 (50%)                               
      Renal, Histiocytic Sarcoma                       1 (100%)                                                                     
                                                             Page   8                                                               
NTP Experiment-Test: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
   Lymph Node, Bronchial                              (21)         (24)         (28)         (25)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (4%)                                
      Histiocytic Sarcoma                              1 (5%)                                                                       
      Sarcoma, Metastatic, Liver                                                              1 (4%)                                
   Lymph Node, Mesenteric                             (49)         (48)         (43)         (47)                                   
      Hemangiosarcoma                                               1 (2%)                                                          
      Hepatoblastoma, Metastatic, Liver                1 (2%)                                                                       
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Sarcoma, Metastatic, Liver                                                              1 (2%)                                
   Lymph Node, Mediastinal                            (43)         (28)         (31)         (35)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (3%)                                
      Hepatocellular Carcinoma, Metastatic, Liver      1 (2%)                                                                       
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                                                                       
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Sarcoma, Metastatic, Liver                                                              1 (3%)                                
   Spleen                                             (47)         (50)         (49)         (50)                                   
      Hemangiosarcoma                                  1 (2%)       3 (6%)       1 (2%)       2 (4%)                                
      Histiocytic Sarcoma                              1 (2%)                                 1 (2%)                                
   Thymus                                             (28)         (31)         (33)         (28)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (49)         (50)         (49)         (49)                                   
      Hemangioma                                       1 (2%)                                                                       
      Hemangiosarcoma                                  1 (2%)       1 (2%)                    2 (4%)                                
      Subcutaneous Tissue, Carcinoma                                                          1 (2%)                                
      Subcutaneous Tissue, Sarcoma                     1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Hemangiosarcoma                                                                         1 (2%)                                
   Skeletal Muscle                                    (1)                                    (2)                                    
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (50%)                               
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page   9                                                               
NTP Experiment-Test: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     9 (18%)      9 (18%)     11 (22%)     13 (26%)                               
      Alveolar/Bronchiolar Adenoma, Multiple                        3 (6%)       2 (4%)       5 (10%)                               
      Alveolar/Bronchiolar Carcinoma                   3 (6%)       5 (10%)      5 (10%)      9 (18%)                               
      Alveolar/Bronchiolar Carcinoma, Multiple         1 (2%)                    2 (4%)       2 (4%)                                
      Hemangiosarcoma, Metastatic, Liver                                                      1 (2%)                                
      Hepatoblastoma, Metastatic, Liver                1 (2%)                                                                       
      Hepatocellular Carcinoma, Metastatic, Liver      5 (10%)      5 (10%)      6 (12%)      7 (14%)                               
      Histiocytic Sarcoma                              1 (2%)                                                                       
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 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (4)          (4)          (4)          (6)                                    
      Adenoma                                          4 (100%)     2 (50%)      2 (50%)      1 (17%)                               
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 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (49)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (2%)                                
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Renal Tubule, Adenoma                                         1 (2%)                    1 (2%)                                
                                                                                                                                    
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 SYSTEMIC LESIONS                                                                                                                   
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                              1 (2%)                                 1 (2%)                                
      Lymphoma Malignant                               1 (2%)       1 (2%)       1 (2%)                                             
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     *   Number of animals with any tissue examined microscopically                                                                 
                                                             Page  10                                                               
NTP Experiment-Test: 05156-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/03/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:41:43  
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         B6C3F1 MICE MALE                          CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
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TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            49          48          47          46                                       
     Total Primary Neoplasms                           77          94          92          95                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 30          30          30          27                                       
     Total Benign Neoplasms                            38          39          42          35                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              33          39          41          38                                       
     Total Malignant Neoplasms                         39          55          50          60                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              7           6           7           9                                       
     Total Metastatic Neoplasm                         14           6           7          21                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    
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a  Number of animals examined microscopically at site and number of animals with lesion                                             
b  Primary tumors: all tumors except metastatic tumors                                                                              
                                                             Page  11                                                               
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NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.