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TDMS Study 05210-04 Pathology Tables

NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56

                                                           CORE STUDY




       Facility:  I. I. T. Research Institute

       Chemical CAS #:  100-41-4

       Lock Date:  10/02/92

       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: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 5            6            1            4                                     
    Natural Death                                      9            6            8            9                                     
    Accidently Killed                                  1                         1                                                  
  Survivors                                                                                                                         
    Terminal Sacrifice                                34           38           40           37                                     
    Natural Death                                      1                                                                            
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (48)         (48)         (50)         (50)                                   
   Gallbladder                                        (44)         (44)         (44)         (46)                                   
   Intestine Large, Rectum                            (49)         (48)         (49)         (47)                                   
   Intestine Large, Cecum                             (49)         (47)         (48)         (44)                                   
   Intestine Small, Duodenum                          (45)         (48)         (47)         (46)                                   
      Polyp Adenomatous                                                          1 (2%)                                             
   Intestine Small, Jejunum                           (46)         (46)         (46)         (45)                                   
   Intestine Small, Ileum                             (47)         (47)         (47)         (46)                                   
   Liver                                              (50)         (50)         (50)         (50)                                   
      Cholangiocarcinoma                                            1 (2%)                                                          
      Fibrosarcoma, Metastatic, Pancreas               1 (2%)                                                                       
      Hemangioma                                                    1 (2%)                                                          
      Hepatocellular Carcinoma                         7 (14%)      4 (8%)       3 (6%)      10 (20%)                               
      Hepatocellular Carcinoma, Multiple                                                      2 (4%)                                
      Hepatocellular Adenoma                           6 (12%)      8 (16%)      9 (18%)     12 (24%)                               
      Hepatocellular Adenoma, Multiple                              1 (2%)       3 (6%)       4 (8%)                                
   Pancreas                                           (50)         (50)         (50)         (49)                                   
      Fibrosarcoma                                     1 (2%)                                                                       
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
   Stomach, Forestomach                               (50)         (49)         (48)         (50)                                   
      Squamous Cell Papilloma                          1 (2%)       2 (4%)       1 (2%)       1 (2%)                                
   Stomach, Glandular                                 (50)         (49)         (48)         (50)                                   
      Serosa, Sarcoma, Metastatic, Uterus                           1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (46)         (48)         (48)         (50)                                   
      Adventitia, Hepatocellular Carcinoma,                                                                                         
          Metastatic, Liver                            1 (2%)                                                                       
   Heart                                              (50)         (49)         (50)         (50)                                   
                                                             Page   2                                                               
NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
CARDIOVASCULAR SYSTEM - cont                                                                                                        
      Fibrosarcoma, Metastatic, Pancreas               1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (47)         (50)         (50)         (49)                                   
      Adenoma                                                                    1 (2%)                                             
   Adrenal Medulla                                    (47)         (50)         (50)         (49)                                   
      Pheochromocytoma Malignant                                                 1 (2%)                                             
      Pheochromocytoma Benign                                       1 (2%)       1 (2%)                                             
   Islets, Pancreatic                                 (50)         (50)         (50)         (49)                                   
      Adenoma                                                                    1 (2%)                                             
   Pituitary Gland                                    (48)         (49)         (47)         (49)                                   
      Pars Distalis, Adenoma                           4 (8%)       8 (16%)      7 (15%)      5 (10%)                               
      Pars Intermedia, Adenoma                                                   1 (2%)                                             
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Follicular Cell, Adenoma                         5 (10%)      4 (8%)       3 (6%)       4 (8%)                                
      Follicular Cell, Adenoma, Multiple                            2 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Tissue NOS                                         (1)          (6)          (4)          (1)                                    
      Hemangiosarcoma                                               1 (17%)                                                         
      Leiomyosarcoma                                   1 (100%)                                                                     
      Abdominal, Osteosarcoma                                       1 (17%)                                                         
      Pelvic, Sarcoma                                                            1 (25%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (41)         (47)         (48)         (48)                                   
      Fibrosarcoma                                                                            1 (2%)                                
   Ovary                                              (49)         (50)         (49)         (49)                                   
      Cystadenoma                                      2 (4%)                                 2 (4%)                                
      Fibrosarcoma, Metastatic, Pancreas               1 (2%)                                                                       
      Granulosa Cell Tumor Benign                      1 (2%)                                                                       
   Uterus                                             (50)         (50)         (50)         (50)                                   
      Leiomyosarcoma                                   1 (2%)                                                                       
      Polyp Stromal                                    2 (4%)       1 (2%)       1 (2%)                                             
      Sarcoma                                                       1 (2%)                                                          
      Endometrium, Adenoma                             1 (2%)                                                                       
      Myometrium, Hemangioma                                                     1 (2%)                                             
   Vagina                                             (1)                                                                           
      Leiomyosarcoma                                   1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page   3                                                               
NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (48)         (50)         (50)         (50)                                   
   Lymph Node                                         (3)          (7)          (2)          (5)                                    
      Iliac, Hemangioma                                             1 (14%)                                                         
      Lumbar, Osteosarcoma, Metastatic, Tissue NOS                  1 (14%)                                                         
      Renal, Hemangiosarcoma                                        1 (14%)                                                         
   Lymph Node, Bronchial                              (32)         (40)         (29)         (38)                                   
      Fibrosarcoma, Metastatic, Pancreas               1 (3%)                                                                       
      Hepatocellular Carcinoma, Metastatic, Liver      1 (3%)                                                                       
   Lymph Node, Mandibular                             (47)         (48)         (47)         (44)                                   
   Lymph Node, Mesenteric                             (48)         (48)         (46)         (44)                                   
      Fibrosarcoma, Metastatic, Pancreas               1 (2%)                                                                       
   Lymph Node, Mediastinal                            (34)         (42)         (41)         (31)                                   
      Fibrosarcoma, Metastatic, Pancreas               1 (3%)                                                                       
      Hepatocellular Carcinoma, Metastatic, Liver      1 (3%)                                                                       
   Spleen                                             (50)         (50)         (50)         (49)                                   
      Capsule, Fibrosarcoma, Metastatic, Pancreas      1 (2%)                                                                       
   Thymus                                             (42)         (44)         (45)         (46)                                   
      Hepatocellular Carcinoma, Metastatic, Liver      1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (49)         (50)         (48)         (49)                                   
      Carcinoma                                        1 (2%)       3 (6%)                                                          
   Skin                                               (50)         (50)         (49)         (50)                                   
      Fibroma                                                                                 1 (2%)                                
      Fibrosarcoma                                                  2 (4%)                                                          
      Fibrous Histiocytoma                                                                    1 (2%)                                
      Hemangioma                                                    1 (2%)       2 (4%)                                             
      Squamous Cell Carcinoma                                       1 (2%)                                                          
      Sebaceous Gland, Adenoma                                                   1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (49)         (50)         (50)         (50)                                   
      Rib, Sarcoma, Metastatic, Tissue NOS                                       1 (2%)                                             
      Vertebra, Osteosarcoma                                                     1 (2%)                                             
   Skeletal Muscle                                                 (2)                                                              
      Carcinoma, Metastatic, Mammary Gland                          1 (50%)                                                         
      Rhabdomyosarcoma                                              1 (50%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page   4                                                               
NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Cerebrum, Oligodendroglioma Benign               1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (49)         (49)         (47)         (48)                                   
   Lung                                               (50)         (50)         (49)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     3 (6%)       4 (8%)       4 (8%)       8 (16%)                               
      Alveolar/Bronchiolar Adenoma, Multiple           1 (2%)                    1 (2%)                                             
      Alveolar/Bronchiolar Carcinoma                                2 (4%)                                                          
      Carcinoma, Metastatic, Harderian Gland           1 (2%)                                                                       
      Carcinoma, Metastatic, Mammary Gland                          1 (2%)                                                          
      Hepatocellular Carcinoma, Metastatic, Liver      3 (6%)       1 (2%)       2 (4%)       1 (2%)                                
      Osteosarcoma, Metastatic, Tissue NOS                          1 (2%)                                                          
      Sarcoma, Metastatic, Tissue NOS                                            1 (2%)                                             
      Sarcoma, Metastatic, Uterus                                   1 (2%)                                                          
      Squamous Cell Carcinoma, Metastatic,                                                                                          
          Lacrimal Gland                                                                      1 (2%)                                
   Nose                                               (49)         (50)         (50)         (50)                                   
      Carcinoma, Metastatic, Harderian Gland           1 (2%)                                                                       
   Pleura                                             (1)                                                                           
      Hepatocellular Carcinoma, Metastatic, Liver      1 (100%)                                                                     
   Trachea                                            (50)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (1)                       (1)          (3)                                    
      Adenoma                                                                    1 (100%)     3 (100%)                              
      Carcinoma                                        1 (100%)                                                                     
   Lacrimal Gland                                                                            (1)                                    
      Squamous Cell Carcinoma                                                                 1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Cholangiocarcinoma, Metastatic, Liver                         1 (2%)                                                          
      Cortex, Fibrosarcoma, Metastatic, Pancreas       1 (2%)                                                                       
   Ureter                                                          (1)                       (1)                                    
   Urinary Bladder                                    (47)         (48)         (47)         (49)                                   
                                                             Page   5                                                               
NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - cont                                                                                                               
      Serosa, Sarcoma, Metastatic, Uterus                           1 (2%)                                                          
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Leukemia Granulocytic                            1 (2%)                                                                       
      Lymphoma Malignant                               3 (6%)       6 (12%)      5 (10%)      5 (10%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                             Page   6                                                               
NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            29          38          31          38                                       
     Total Primary Neoplasms                           44          58          50          60                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 20          26          27          28                                       
     Total Benign Neoplasms                            27          34          39          40                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              13          20           9          18                                       
     Total Malignant Neoplasms                         17          24          11          20                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              5           5           3           2                                       
     Total Metastatic Neoplasm                         18           9           4           2                                       
                                                                                                                                    
   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: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 6            2            5            6                                     
    Natural Death                                     15           12           13           13                                     
    Accidently Killed                                  1                                      1                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                28           36           31           30                                     
    Natural Death                                                                1                                                  
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (42)         (46)         (44)         (43)                                   
   Intestine Small, Jejunum                           (44)         (46)         (44)         (43)                                   
      Epithelium, Carcinoma                                         1 (2%)                                                          
   Intestine Small, Ileum                             (42)         (46)         (44)         (41)                                   
   Liver                                              (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (2%)                                
      Cholangiocarcinoma                                            1 (2%)                                                          
      Fibrosarcoma, Metastatic, Stomach, Glandular     1 (2%)                                                                       
      Hemangioma                                       1 (2%)                                                                       
      Hemangiosarcoma                                               1 (2%)                                                          
      Hepatoblastoma                                                1 (2%)                                                          
      Hepatocellular Carcinoma                        17 (34%)      8 (16%)     11 (22%)     10 (20%)                               
      Hepatocellular Carcinoma, Multiple                            1 (2%)       2 (4%)                                             
      Hepatocellular Adenoma                          11 (22%)     12 (24%)     17 (34%)     17 (34%)                               
      Hepatocellular Adenoma, Multiple                 1 (2%)       4 (8%)                    1 (2%)                                
      Hepatocholangiocarcinoma                         1 (2%)                    1 (2%)       1 (2%)                                
   Mesentery                                          (1)                       (1)                                                 
      Hepatocellular Carcinoma, Metastatic, Liver      1 (100%)                                                                     
      Hepatocholangiocarcinoma, Metastatic, Liver                                1 (100%)                                           
   Pancreas                                           (49)         (50)         (48)         (48)                                   
      Acinus, Hepatocholangiocarcinoma, Metastatic,                                                                                 
           Liver                                                                 1 (2%)                                             
   Stomach, Forestomach                               (48)         (50)         (50)         (47)                                   
      Fibrosarcoma, Metastatic, Stomach, Glandular     1 (2%)                                                                       
      Squamous Cell Papilloma                                       1 (2%)                                                          
   Stomach, Glandular                                 (48)         (50)         (50)         (47)                                   
      Fibrosarcoma                                     1 (2%)                                                                       
   Tooth                                                                        (1)          (1)                                    
      Odontoma                                                                                1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                             Page   8                                                               
NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (48)         (48)         (49)         (47)                                   
      Aorta, Fibrosarcoma, Metastatic, Stomach,                                                                                     
           Glandular                                   1 (2%)                                                                       
      Aorta, Hepatocellular Carcinoma, Metastatic,                                                                                  
           Liver                                       1 (2%)                                                                       
      Aorta, Sarcoma                                                                          1 (2%)                                
   Heart                                              (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (2%)                                
      Fibrosarcoma, Metastatic, Stomach, Glandular     1 (2%)                                                                       
      Hepatocholangiocarcinoma, Metastatic, Liver                                1 (2%)                                             
      Pericardium, Hepatocholangiocarcinoma,                                                                                        
          Metastatic, Liver                            1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (47)         (47)         (48)         (48)                                   
      Adenoma                                          1 (2%)                    1 (2%)                                             
      Carcinoma                                                                  1 (2%)                                             
      Hepatocellular Carcinoma, Metastatic, Liver      1 (2%)                                                                       
   Islets, Pancreatic                                 (49)         (50)         (48)         (48)                                   
      Adenoma                                                                                 1 (2%)                                
      Carcinoma                                                                               1 (2%)                                
   Pituitary Gland                                    (44)         (45)         (45)         (47)                                   
      Pars Distalis, Carcinoma                                                   1 (2%)                                             
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Follicular Cell, Adenoma                         3 (6%)       2 (4%)       1 (2%)       5 (10%)                               
      Follicular Cell, Adenoma, Multiple                                                      1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Tissue NOS                                         (2)          (3)          (1)          (2)                                    
      Fibrosarcoma                                     1 (50%)                                                                      
      Fat, Hepatocholangiocarcinoma, Metastatic,                                                                                    
           Liver                                                                 1 (100%)                                           
      Thoracic, Hepatocholangiocarcinoma,                                                                                           
          Metastatic, Liver                            1 (50%)                                                                      
      Thoracic, Sarcoma                                                                       1 (50%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page   9                                                               
NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (49)         (50)         (50)         (50)                                   
      Leiomyoma                                                     1 (2%)                                                          
   Seminal Vesicle                                    (49)         (50)         (50)         (50)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver                                1 (2%)                                             
   Testes                                             (49)         (50)         (50)         (50)                                   
      Interstitial Cell, Adenoma                       1 (2%)                    1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
   Lymph Node                                         (4)          (7)          (11)         (3)                                    
      Fibrosarcoma, Metastatic, Stomach, Glandular     1 (25%)                                                                      
      Pancreatic, Carcinoma                                                                   1 (33%)                               
      Popliteal, Hemangioma                                                      1 (9%)                                             
      Renal, Cholangiocarcinoma, Metastatic, Liver                  1 (14%)                                                         
      Renal, Fibrosarcoma, Metastatic, Stomach,                                                                                     
           Glandular                                   1 (25%)                                                                      
      Renal, Hepatocholangiocarcinoma, Metastatic,                                                                                  
           Liver                                                                 1 (9%)                                             
   Lymph Node, Bronchial                              (14)         (24)         (27)         (27)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (4%)                                
      Fibrosarcoma, Metastatic, Stomach, Glandular     1 (7%)                                                                       
      Hepatocholangiocarcinoma, Metastatic, Liver                                1 (4%)                                             
      Sarcoma                                                                                 1 (4%)                                
   Lymph Node, Mandibular                             (43)         (45)         (46)         (44)                                   
      Sarcoma, Metastatic, Nose                        1 (2%)                                                                       
   Lymph Node, Mesenteric                             (45)         (46)         (47)         (48)                                   
      Hepatocholangiocarcinoma, Metastatic, Liver                                1 (2%)                                             
   Lymph Node, Mediastinal                            (24)         (25)         (27)         (25)                                   
      Fibrosarcoma, Metastatic, Stomach, Glandular     1 (4%)                                                                       
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (4%)                                                                       
      Sarcoma                                                                                 1 (4%)                                
   Spleen                                             (50)         (50)         (49)         (49)                                   
   Thymus                                             (37)         (37)         (39)         (34)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (3%)                                
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (3%)                                                                       
      Sarcoma                                                                                 1 (3%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page  10                                                               
NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (50)         (50)         (50)                                   
      Fibrosarcoma                                     1 (2%)                                                                       
      Hemangioma                                                                 1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (49)         (50)         (50)                                   
      Sternum, Fibrosarcoma, Metastatic, Stomach,                                                                                   
           Glandular                                   1 (2%)                                                                       
   Skeletal Muscle                                    (2)                       (2)                                                 
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                  1 (50%)                                            
      Fibrosarcoma, Metastatic, Stomach, Glandular     1 (50%)                                                                      
      Hepatocellular Carcinoma, Metastatic, Liver      1 (50%)                                                                      
      Hepatocholangiocarcinoma, Metastatic, Liver                                1 (50%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     5 (10%)      8 (16%)      9 (18%)     15 (30%)                               
      Alveolar/Bronchiolar Adenoma, Multiple                        1 (2%)       1 (2%)       1 (2%)                                
      Alveolar/Bronchiolar Carcinoma                   2 (4%)       1 (2%)       5 (10%)      3 (6%)                                
      Cholangiocarcinoma, Metastatic, Liver                         1 (2%)                                                          
      Fibrosarcoma, Metastatic, Stomach, Glandular     1 (2%)                                                                       
      Hepatocellular Carcinoma, Metastatic, Liver      5 (10%)      3 (6%)       5 (10%)      3 (6%)                                
      Hepatocholangiocarcinoma, Metastatic, Liver      1 (2%)                    1 (2%)       1 (2%)                                
      Bronchiole, Polyp Adenomatous                                 1 (2%)                                                          
      Mediastinum, Sarcoma                                                                    1 (2%)                                
   Nose                                               (50)         (50)         (50)         (50)                                   
      Sarcoma                                          1 (2%)                                                                       
   Pleura                                                                                    (1)                                    
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                             Page  11                                                               
NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (2)          (3)          (2)                                                 
      Adenoma                                          1 (50%)      3 (100%)     2 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                  1 (2%)       1 (2%)                                
      Cholangiocarcinoma, Metastatic, Liver                         1 (2%)                                                          
      Fibrosarcoma, Metastatic, Stomach, Glandular     1 (2%)                                                                       
      Hepatocellular Carcinoma, Metastatic, Liver      1 (2%)       1 (2%)                                                          
      Renal Tubule, Adenoma                                                      1 (2%)                                             
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Leukemia Granulocytic                                                      1 (2%)       1 (2%)                                
      Lymphoma Malignant                               2 (4%)       2 (4%)       3 (6%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                             Page  12                                                               
NTP Experiment-Test: 05210-04  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:10:56  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      75 PPM       250          750                                       
                                                                             PPM          PPM                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            35          34          40          41                                       
     Total Primary Neoplasms                           50          49          60          68                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 20          25          26          30                                       
     Total Benign Neoplasms                            24          33          35          43                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              21          15          21          16                                       
     Total Malignant Neoplasms                         26          16          25          25                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              9           4           6           5                                       
     Total Metastatic Neoplasm                         28           7          17          10                                       
                                                                                                                                    
   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  13                                                               
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