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TDMS Study 05180-06 Pathology Tables

NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30

                                                      2 YEAR CHRONIC RATS




       Facility:  Battelle Northwest

       Chemical CAS #:  1303-00-0000

       Lock Date:  03/13/97

       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: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 

  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                30           30           23           35                                     
    Natural Death                                      1            3            6            4                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                19           17           20           11                                     
    Natural Death                                                                1                                                  

  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (50)         (49)         (48)         (49)                                   
   Intestine Large, Rectum                            (50)         (49)         (49)         (49)                                   
      Carcinoma                                                                               1 (2%)                                
   Intestine Large, Cecum                             (50)         (49)         (48)         (49)                                   
   Intestine Small, Duodenum                          (50)         (48)         (48)         (49)                                   
      Leiomyoma                                        1 (2%)                                                                       
   Intestine Small, Jejunum                           (50)         (48)         (46)         (49)                                   
      Leiomyosarcoma                                                             1 (2%)                                             
   Intestine Small, Ileum                             (50)         (49)         (46)         (49)                                   
   Liver                                              (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                           1 (2%)       1 (2%)                                             
   Mesentery                                          (6)          (14)         (6)          (11)                                   
   Oral Mucosa                                        (1)          (2)                                                              
      Gingival, Squamous Cell Carcinoma                             1 (50%)                                                         
      Pharyngeal, Squamous Cell Carcinoma                           1 (50%)                                                         
      Pharyngeal, Squamous Cell Papilloma              1 (100%)                                                                     
   Pancreas                                           (50)         (50)         (50)         (49)                                   
   Salivary Glands                                    (50)         (49)         (50)         (50)                                   
   Stomach, Forestomach                               (50)         (50)         (50)         (50)                                   
   Stomach, Glandular                                 (50)         (50)         (50)         (49)                                   
   Tongue                                                          (1)          (2)                                                 
      Squamous Cell Papilloma                                                    1 (50%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (49)                                   
   Adrenal Medulla                                    (50)         (49)         (50)         (49)                                   
      Pheochromocytoma Malignant                                    1 (2%)                                                          
      Pheochromocytoma Benign                          4 (8%)       5 (10%)      4 (8%)       8 (16%)                               
      Bilateral, Pheochromocytoma Benign                                         2 (4%)       5 (10%)                               
   Islets, Pancreatic                                 (50)         (50)         (50)         (49)                                   
      Adenoma                                          1 (2%)                                 2 (4%)                                
      Carcinoma                                                                               1 (2%)                                
   Pituitary Gland                                    (50)         (50)         (50)         (49)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
      Pars Distalis, Adenoma                          42 (84%)     43 (86%)     36 (72%)     31 (63%)                               
   Thyroid Gland                                      (50)         (49)         (48)         (49)                                   
      C-Cell, Adenoma                                  7 (14%)      4 (8%)       4 (8%)       1 (2%)                                
      C-Cell, Carcinoma                                2 (4%)       1 (2%)       2 (4%)       3 (6%)                                
      Follicular Cell, Adenoma                         2 (4%)                                 1 (2%)                                
      Follicular Cell, Carcinoma                                    1 (2%)       1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (50)         (48)         (47)         (48)                                   
      Adenoma                                          7 (14%)      9 (19%)      7 (15%)      4 (8%)                                
      Carcinoma                                        3 (6%)       2 (4%)       2 (4%)       2 (4%)                                
      Bilateral, Adenoma                               1 (2%)                                                                       
   Ovary                                              (50)         (50)         (50)         (49)                                   
      Granulosa Cell Tumor Malignant                                             1 (2%)                                             
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Uterus                                             (50)         (50)         (49)         (50)                                   
      Leiomyoma                                                                               1 (2%)                                
      Leiomyosarcoma                                                                          1 (2%)                                
      Polyp Stromal                                    7 (14%)      6 (12%)      6 (12%)      2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (49)         (50)         (49)                                   
   Lymph Node                                         (3)          (6)          (3)          (5)                                    
      Pancreatic, Histiocytic Sarcoma                                            1 (33%)                                            
   Lymph Node, Bronchial                              (36)         (36)         (39)         (40)                                   
      Histiocytic Sarcoma                                           1 (3%)       1 (3%)                                             
   Lymph Node, Mandibular                             (43)         (45)         (45)         (47)                                   
NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Lymph Node, Mesenteric                             (50)         (50)         (50)         (49)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Lymph Node, Mediastinal                            (34)         (39)         (39)         (39)                                   
      Histiocytic Sarcoma                                           1 (3%)       1 (3%)                                             
   Spleen                                             (50)         (50)         (50)         (49)                                   
      Histiocytic Sarcoma                                           1 (2%)       1 (2%)                                             
   Thymus                                             (45)         (48)         (41)         (45)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
      Thymoma Benign                                   1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (50)         (50)         (50)                                   
      Adenoma                                                                                 1 (2%)                                
      Carcinoma                                        8 (16%)      2 (4%)       7 (14%)      4 (8%)                                
      Carcinoma, Multiple                                           1 (2%)                    1 (2%)                                
      Fibroadenoma                                    21 (42%)     24 (48%)     18 (36%)     23 (46%)                               
      Fibroadenoma, Multiple                           5 (10%)      7 (14%)     11 (22%)      8 (16%)                               
   Skin                                               (50)         (50)         (50)         (50)                                   
      Basal Cell Adenoma                                                                      1 (2%)                                
      Basal Cell Carcinoma                                                       1 (2%)                                             
      Squamous Cell Papilloma                                                    1 (2%)                                             
      Subcutaneous Tissue, Fibroma                     1 (2%)                    2 (4%)       1 (2%)                                
      Subcutaneous Tissue, Lipoma                                                             1 (2%)                                
      Subcutaneous Tissue, Rhabdomyosarcoma                                      1 (2%)                                             
      Subcutaneous Tissue, Sarcoma                                               1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Meningioma Malignant, Metastatic, Brain                                    1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
      Meningioma Malignant                                                       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (50)         (50)         (49)                                   
      Carcinoma, Metastatic, Thyroid Gland                                                    1 (2%)                                
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                                               2 (4%)       7 (14%)                               
      Alveolar/Bronchiolar Carcinoma                                             2 (4%)       3 (6%)                                
      Carcinoma, Metastatic, Mammary Gland                          1 (2%)                                                          
      Carcinoma, Metastatic, Thyroid Gland                                                    1 (2%)                                
      Histiocytic Sarcoma                                           1 (2%)       1 (2%)                                             
      Squamous Cell Carcinoma                                                                 1 (2%)                                
   Nose                                               (50)         (50)         (49)         (49)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Zymbal's Gland                                                  (1)                                                              
      Carcinoma                                                     1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (49)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
      Renal Tubule, Adenoma                                                      1 (2%)                                             
   Urinary Bladder                                    (50)         (50)         (50)         (49)                                   
      Leiomyoma                                                                  1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   

   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                                           2 (4%)       1 (2%)                                             
      Leukemia Mononuclear                            22 (44%)     21 (42%)     18 (36%)     33 (66%)                               
____________________________________________________________________________________________________________________________________
     *   Number of animals with any tissue examined microscopically                                                                 


                                                             Page   5                                                               
NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            48          49          49          47                                       
     Total Primary Neoplasms                          136         132         135         148                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 48          46          43          43                                       
     Total Benign Neoplasms                           101          98          96          97                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              28          28          32          38                                       
     Total Malignant Neoplasms                         35          34          39          51                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms                          1           1           1                                       
     Total Metastatic Neoplasm                                      1           1           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                                                                              
NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 

  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                30           29           32           33                                     
    Natural Death                                      7            8            3            4                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                13           13           15           13                                     

  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (49)         (50)         (50)         (50)                                   
   Intestine Large, Colon                             (47)         (47)         (48)         (50)                                   
   Intestine Large, Rectum                            (48)         (49)         (47)         (49)                                   
   Intestine Large, Cecum                             (46)         (43)         (48)         (49)                                   
   Intestine Small, Duodenum                          (48)         (48)         (49)         (50)                                   
   Intestine Small, Jejunum                           (45)         (43)         (48)         (50)                                   
   Intestine Small, Ileum                             (44)         (43)         (48)         (49)                                   
      Polyp Adenomatous                                             1 (2%)                                                          
   Liver                                              (50)         (50)         (50)         (50)                                   
      Cholangioma                                                                             1 (2%)                                
      Hepatocellular Carcinoma                                                   1 (2%)                                             
      Hepatocellular Adenoma                           1 (2%)       1 (2%)       1 (2%)                                             
      Osteosarcoma, Metastatic, Bone                                             1 (2%)                                             
   Mesentery                                          (5)          (10)         (14)         (7)                                    
      Carcinoma, Metastatic, Uncertain Primary Site                                           1 (14%)                               
   Oral Mucosa                                        (1)          (3)                       (1)                                    
      Gingival, Squamous Cell Papilloma                                                       1 (100%)                              
      Pharyngeal, Squamous Cell Papilloma                           3 (100%)                                                        
   Pancreas                                           (49)         (49)         (50)         (50)                                   
      Adenoma                                          2 (4%)       1 (2%)       1 (2%)       1 (2%)                                
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
   Stomach, Forestomach                               (49)         (50)         (50)         (50)                                   
      Squamous Cell Papilloma                                                                 1 (2%)                                
   Stomach, Glandular                                 (49)         (49)         (50)         (50)                                   
   Tongue                                             (2)                       (2)          (1)                                    
      Squamous Cell Carcinoma                          1 (50%)                                                                      
      Squamous Cell Papilloma                          1 (50%)                   1 (50%)      1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (3)          (4)          (6)          (6)                                    
      Hemangiosarcoma                                                            1 (17%)                                            
   Heart                                              (50)         (50)         (50)         (50)                                   
      Schwannoma Malignant                             1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (49)         (49)         (49)         (50)                                   
      Osteosarcoma, Metastatic, Bone                                             1 (2%)                                             
   Adrenal Medulla                                    (50)         (49)         (49)         (50)                                   
      Pheochromocytoma Malignant                       2 (4%)                    3 (6%)       1 (2%)                                
      Pheochromocytoma Benign                         12 (24%)      9 (18%)     17 (35%)     10 (20%)                               
      Bilateral, Pheochromocytoma Benign               4 (8%)       3 (6%)       5 (10%)      3 (6%)                                
   Islets, Pancreatic                                 (48)         (49)         (50)         (50)                                   
      Adenoma                                          2 (4%)       1 (2%)       2 (4%)       2 (4%)                                
      Carcinoma                                                     3 (6%)                    1 (2%)                                
   Pituitary Gland                                    (49)         (49)         (50)         (50)                                   
      Pars Distalis, Adenoma                          21 (43%)     22 (45%)     21 (42%)     19 (38%)                               
   Thyroid Gland                                      (46)         (46)         (49)         (50)                                   
      C-Cell, Adenoma                                  3 (7%)       5 (11%)      6 (12%)      2 (4%)                                
      C-Cell, Carcinoma                                             3 (7%)       2 (4%)       1 (2%)                                
      Follicular Cell, Adenoma                         1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                         (1)                       (1)                                                 
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (50)         (50)         (50)                                   
   Preputial Gland                                    (50)         (49)         (50)         (49)                                   
      Adenoma                                                       2 (4%)       3 (6%)       6 (12%)                               
      Carcinoma                                        4 (8%)       4 (8%)       5 (10%)      4 (8%)                                
   Prostate                                           (50)         (48)         (50)         (50)                                   
      Adenoma                                                       2 (4%)                                                          
      Histiocytic Sarcoma                                                        1 (2%)                                             
   Seminal Vesicle                                    (45)         (47)         (48)         (50)                                   
   Testes                                             (50)         (50)         (50)         (50)                                   
      Bilateral, Interstitial Cell, Adenoma           42 (84%)     35 (70%)     37 (74%)     33 (66%)                               
      Interstitial Cell, Adenoma                       3 (6%)       5 (10%)      9 (18%)      8 (16%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (49)         (48)         (50)         (50)                                   
   Lymph Node                                         (12)         (8)          (9)          (5)                                    
      Schwannoma Malignant, Metastatic, Heart          1 (8%)                                                                       
      Inguinal, Fibrosarcoma, Metastatic, Skin                      1 (13%)                                                         
      Renal, Pheochromocytoma Malignant,                                                                                            
          Metastatic, Adrenal Medulla                  1 (8%)                                                                       
   Lymph Node, Bronchial                              (36)         (37)         (35)         (42)                                   
      Plasma Cell Tumor Malignant                      1 (3%)                                                                       
   Lymph Node, Mandibular                             (46)         (43)         (46)         (44)                                   
   Lymph Node, Mesenteric                             (48)         (48)         (50)         (48)                                   
   Lymph Node, Mediastinal                            (42)         (40)         (46)         (47)                                   
      Plasma Cell Tumor Malignant                      1 (2%)                                                                       
   Spleen                                             (50)         (50)         (50)         (50)                                   
      Osteosarcoma                                                                            1 (2%)                                
      Osteosarcoma, Metastatic, Bone                                             1 (2%)                                             
      Sarcoma                                                                                 1 (2%)                                
   Thymus                                             (46)         (45)         (45)         (42)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (41)         (42)         (42)         (40)                                   
      Carcinoma                                                                               1 (3%)                                
      Fibroadenoma                                                  2 (5%)       3 (7%)       2 (5%)                                
   Skin                                               (50)         (49)         (50)         (50)                                   
      Basal Cell Adenoma                               1 (2%)                                 1 (2%)                                
      Keratoacanthoma                                  3 (6%)       2 (4%)       4 (8%)       3 (6%)                                
      Squamous Cell Carcinoma                          1 (2%)                                 1 (2%)                                
      Squamous Cell Papilloma                                       2 (4%)       1 (2%)       1 (2%)                                
      Trichoepithelioma                                                                       1 (2%)                                
      Subcutaneous Tissue, Fibroma                     3 (6%)       1 (2%)       2 (4%)       1 (2%)                                
      Subcutaneous Tissue, Fibrosarcoma                             1 (2%)       2 (4%)                                             
      Subcutaneous Tissue, Hemangioma                                                         1 (2%)                                
      Subcutaneous Tissue, Hemangiopericytoma                                                 1 (2%)                                
      Subcutaneous Tissue, Liposarcoma                              1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Osteosarcoma                                     1 (2%)                    2 (4%)                                             
   Skeletal Muscle                                    (1)                                                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Astrocytoma Malignant                                         1 (2%)                                                          
      Hemangioma                                                                              1 (2%)                                
      Oligodendroglioma Malignant                                                1 (2%)       1 (2%)                                
      Sarcoma                                                                                 1 (2%)                                
   Peripheral Nerve                                                (1)                                                              
      Schwannoma Malignant                                          1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (50)         (49)         (50)                                   
   Lung                                               (50)         (49)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     1 (2%)                    3 (6%)       1 (2%)                                
      Alveolar/Bronchiolar Adenoma, Multiple                                                  1 (2%)                                
      Alveolar/Bronchiolar Carcinoma                   2 (4%)                    2 (4%)       1 (2%)                                
      Carcinoma, Metastatic, Thyroid Gland                          1 (2%)                                                          
      Chordoma, Metastatic, Uncertain Primary Site                  1 (2%)                                                          
      Osteosarcoma, Metastatic, Bone                                             1 (2%)                                             
      Pheochromocytoma Malignant, Metastatic,                                                                                       
          Adrenal Medulla                              2 (4%)                                                                       
      Plasma Cell Tumor Malignant, Metastatic,                                                                                      
           Lymph Node, Mediastinal                     1 (2%)                                                                       
      Squamous Cell Carcinoma                          1 (2%)                                                                       
      Mediastinum, Sarcoma                                                       1 (2%)                                             
   Nose                                               (50)         (48)         (49)         (50)                                   
   Pleura                                                          (1)                                                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Zymbal's Gland                                     (1)          (1)                                                              
      Carcinoma                                        1 (100%)     1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (49)         (50)         (50)         (50)                                   
      Renal Tubule, Adenoma                            1 (2%)                                 3 (6%)                                
      Renal Tubule, Adenoma, Multiple                  1 (2%)                                                                       
      Transitional Epithelium, Papilloma                                         1 (2%)                                             
   Urinary Bladder                                    (48)         (50)         (50)         (50)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - cont                                                                                                               
      Transitional Epithelium, Papilloma                                         1 (2%)       1 (2%)                                
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   

   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                                                        1 (2%)                                             
      Leukemia Mononuclear                            19 (38%)     28 (56%)     33 (66%)     28 (56%)                               
      Mesothelioma Benign                              1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Mesothelioma Malignant                           1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
     *   Number of animals with any tissue examined microscopically                                                                 


                                                             Page  11                                                               
NTP Experiment-Test: 05180-06  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 02/17/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:15:30  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      0.01         0.1          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            50          49          50          48                                       
     Total Primary Neoplasms                          139         142         173         149                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 50          47          49          46                                       
     Total Benign Neoplasms                           103          98         119         107                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              30          38          41          34                                       
     Total Malignant Neoplasms                         36          44          54          42                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              3           4           1           1                                       
     Total Metastatic Neoplasm                          5           6           4           1                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms                           1                       1                                       
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    

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