National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/17641

TDMS Study 88004-05 Pathology Tables

NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06

                                                         FINAL #1 RATS




       Facility:  Battelle Northwest

       Chemical CAS #:  1321-74-0

       Lock Date:  04/16/02

       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: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                10           16           14           26                                     
    Natural Death                                      7            3            3            2                                     
    Accidently Killed                                               1                                                               
  Survivors                                                                                                                         
    Terminal Sacrifice                                33           30           33           22                                     
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (50)         (49)         (49)         (50)                                   
      Epithelium, Metaplasia, Focal, Squamous                       1 (2%)                                                          
   Liver                                              (50)         (50)         (50)         (50)                                   
      Clear Cell Focus                                 5 (10%)      7 (14%)      6 (12%)                                            
      Hepatodiaphragmatic Nodule                       5 (10%)      7 (14%)      6 (12%)      9 (18%)                               
      Necrosis                                                                   1 (2%)                                             
      Vacuolization Cytoplasmic                        4 (8%)       3 (6%)                    3 (6%)                                
      Bile Duct, Hyperplasia                                                     1 (2%)                                             
      Hepatocyte, Regeneration                                      1 (2%)       1 (2%)                                             
      Periportal, Inflammation, Chronic                3 (6%)       2 (4%)       1 (2%)       2 (4%)                                
      Portal, Bile Stasis                              1 (2%)       3 (6%)       2 (4%)       1 (2%)                                
      Serosa, Fibrosis                                                           1 (2%)                                             
   Mesentery                                          (15)         (20)         (17)         (6)                                    
      Necrosis                                        14 (93%)     20 (100%)    16 (94%)      6 (100%)                              
   Oral Mucosa                                        (1)                                                                           
      Pharyngeal, Ulcer                                1 (100%)                                                                     
   Pancreas                                           (50)         (49)         (50)         (50)                                   
      Acinus, Atrophy                                  3 (6%)       5 (10%)      2 (4%)       4 (8%)                                
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
      Inflammation, Chronic                                         1 (2%)                                                          
   Stomach, Forestomach                               (50)         (50)         (49)         (49)                                   
      Hyperplasia, Focal, Squamous                                  1 (2%)       1 (2%)                                             
      Ulcer                                            1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
   Stomach, Glandular                                 (50)         (50)         (49)         (49)                                   
      Erosion                                                                    1 (2%)       1 (2%)                                
      Ulcer                                                                      1 (2%)                                             
      Epithelium, Hyperplasia                          1 (2%)                                                                       
   Tongue                                             (1)          (1)          (3)          (3)                                    
      Epithelium, Hyperplasia                          1 (100%)                  3 (100%)     2 (67%)                               
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    2                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
   Tooth                                                                        (1)                                                 
      Peridontal Tissue, Inflammation                                            1 (100%)                                           
      Pulp, Inflammation, Suppurative                                            1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                                                          3 (6%)                                
      Atrium, Thrombosis                                            1 (2%)       2 (4%)                                             
      Pericardium, Infiltration Cellular, Lymphoid                                            1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Accessory Adrenal Cortical Nodule                                          1 (2%)                                             
      Hemorrhage                                                    1 (2%)                                                          
      Hyperplasia                                                                             1 (2%)                                
      Necrosis                                                      1 (2%)                                                          
      Vacuolization Cytoplasmic                       14 (28%)      5 (10%)      7 (14%)     12 (24%)                               
   Adrenal Medulla                                    (50)         (50)         (50)         (50)                                   
      Hyperplasia                                      1 (2%)       1 (2%)       5 (10%)      2 (4%)                                
   Parathyroid Gland                                  (49)         (49)         (47)         (49)                                   
      Hyperplasia                                                                1 (2%)                                             
   Pituitary Gland                                    (50)         (50)         (50)         (50)                                   
      Cyst                                             6 (12%)      6 (12%)      1 (2%)       5 (10%)                               
      Pars Distalis, Angiectasis                       1 (2%)                                                                       
      Pars Distalis, Hematocyst                                                               1 (2%)                                
      Pars Distalis, Hyperplasia                       4 (8%)       8 (16%)      4 (8%)       7 (14%)                               
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Ultimobranchial Cyst                             1 (2%)                                                                       
      C-Cell, Hyperplasia                              5 (10%)      8 (16%)      6 (12%)      1 (2%)                                
      Follicular Cell, Hyperplasia                                  1 (2%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    3                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
   Clitoral Gland                                     (50)         (50)         (50)         (50)                                   
      Cyst                                             3 (6%)                    1 (2%)                                             
      Hyperplasia                                      1 (2%)       3 (6%)       2 (4%)       2 (4%)                                
      Inflammation, Chronic                            2 (4%)       1 (2%)       1 (2%)                                             
   Ovary                                              (50)         (50)         (50)         (50)                                   
      Cyst                                             5 (10%)      6 (12%)     11 (22%)      4 (8%)                                
      Bilateral, Cyst                                  1 (2%)                                                                       
   Uterus                                             (50)         (50)         (50)         (50)                                   
      Hemorrhage                                                                 1 (2%)                                             
      Necrosis                                                      1 (2%)                                                          
      Endometrium, Hyperplasia                         2 (4%)       1 (2%)       1 (2%)       2 (4%)                                
      Myometrium, Hyperplasia                                                    1 (2%)                                             
   Vagina                                                          (2)                       (3)                                    
      Inflammation, Suppurative                                     1 (50%)                                                         
      Muscularis, Hypertrophy                                                                 1 (33%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Myelofibrosis                                                              1 (2%)                                             
   Lymph Node                                         (6)          (10)         (9)          (8)                                    
      Deep Cervical, Infiltration Cellular,                                                                                         
        Histiocyte                                                  3 (30%)                   1 (13%)                               
      Pancreatic, Pigmentation                                      1 (10%)      1 (11%)                                            
   Lymph Node, Bronchial                              (8)          (9)          (5)          (14)                                   
      Infiltration Cellular, Histiocyte                                                       1 (7%)                                
   Lymph Node, Mesenteric                             (50)         (50)         (50)         (50)                                   
      Infiltration Cellular, Histiocyte                2 (4%)       1 (2%)       2 (4%)                                             
      Pigmentation                                                                            1 (2%)                                
   Lymph Node, Mediastinal                            (32)         (37)         (44)         (34)                                   
      Fibrosis                                                                   1 (2%)                                             
      Hyperplasia, Lymphoid                            1 (3%)                    1 (2%)                                             
      Infiltration Cellular, Histiocyte                2 (6%)       1 (3%)                                                          
      Inflammation, Suppurative                        1 (3%)                                                                       
   Spleen                                             (50)         (50)         (50)         (50)                                   
      Accessory Spleen                                 2 (4%)       1 (2%)       1 (2%)                                             
      Fibrosis                                         3 (6%)       1 (2%)       3 (6%)       1 (2%)                                
      Hematopoietic Cell Proliferation                              1 (2%)                                                          
      Hemorrhage                                       2 (4%)       1 (2%)       1 (2%)       2 (4%)                                
      Hyperplasia, Focal, Lymphoid                                  2 (4%)                                                          
      Inflammation, Chronic Active                                               1 (2%)                                             
      Necrosis                                                                                1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    4                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
   Thymus                                             (45)         (41)         (46)         (39)                                   
      Cyst                                                                                    1 (3%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (50)         (50)         (50)                                   
      Galactocele                                      1 (2%)       2 (4%)                                                          
      Hyperplasia                                                                1 (2%)                                             
      Inflammation, Chronic                                                      1 (2%)                                             
   Skin                                               (50)         (50)         (50)         (50)                                   
      Cyst Epithelial Inclusion                                     2 (4%)                    1 (2%)                                
      Hyperkeratosis                                                1 (2%)                                                          
      Inflammation, Granulomatous                                                             1 (2%)                                
      Ulcer                                            1 (2%)                    1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Joint, Fracture                                               1 (2%)                                                          
      Tibia, Fracture                                                            1 (2%)                                             
   Skeletal Muscle                                    (2)          (3)          (7)          (5)                                    
      Inflammation, Chronic                                         1 (33%)                                                         
      Necrosis                                         1 (50%)      1 (33%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Compression                                      9 (18%)     10 (20%)     11 (22%)      7 (14%)                               
      Congestion                                                    1 (2%)                                                          
      Hemorrhage                                       2 (4%)       2 (4%)       6 (12%)      3 (6%)                                
      Infarct                                                                    1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (50)         (49)         (50)                                   
      Foreign Body                                                  1 (2%)       3 (6%)                                             
      Inflammation, Suppurative                                     2 (4%)       1 (2%)                                             
      Epiglottis, Metaplasia, Squamous                 1 (2%)                                                                       
   Lung                                               (50)         (50)         (50)         (50)                                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    5                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Atrophy                                          1 (2%)                                                                       
      Cyst                                                                       1 (2%)                                             
      Foreign Body                                                               1 (2%)                                             
      Hemorrhage                                       1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Infiltration Cellular, Histiocyte                1 (2%)                                                                       
      Inflammation, Chronic                                                      1 (2%)                                             
      Inflammation, Chronic, Diffuse                   1 (2%)                                 1 (2%)                                
      Inflammation, Chronic, Focal                    27 (54%)     22 (44%)     26 (52%)     33 (66%)                               
      Alveolar Epithelium, Hyperplasia                 4 (8%)       2 (4%)       3 (6%)       1 (2%)                                
      Alveolar Epithelium, Hypertrophy                 1 (2%)       1 (2%)                    1 (2%)                                
      Alveolus, Infiltration Cellular, Focal,                                                                                       
        Histiocyte                                     8 (16%)      3 (6%)       6 (12%)      5 (10%)                               
      Interstitium, Fibrosis                                                                  1 (2%)                                
      Mediastinum, Necrosis, Fatty                     1 (2%)                                                                       
   Nose                                               (50)         (50)         (49)         (49)                                   
      Foreign Body                                     1 (2%)       5 (10%)      1 (2%)                                             
      Inflammation, Suppurative                        5 (10%)     12 (24%)      8 (16%)      7 (14%)                               
      Ulcer                                            1 (2%)                                                                       
      Glands, Dilatation                                           17 (34%)     38 (78%)     44 (90%)                               
      Goblet Cell, Hyperplasia                         1 (2%)       3 (6%)       1 (2%)       4 (8%)                                
      Nasolacrimal Duct, Inflammation, Suppurative     3 (6%)       1 (2%)       3 (6%)       1 (2%)                                
      Nasopharyngeal Duct, Inflammation,                                                                                            
        Suppurative                                                              1 (2%)                                             
      Olfactory Epithelium, Degeneration                           50 (100%)    49 (100%)    48 (98%)                               
      Olfactory Epithelium, Degeneration, Hyaline     10 (20%)     14 (28%)     15 (31%)      4 (8%)                                
      Olfactory Epithelium, Hyperplasia, Basal Cell                25 (50%)     42 (86%)     45 (92%)                               
      Olfactory Epithelium, Regeneration, Focal        1 (2%)                                                                       
      Respiratory Epithelium, Degeneration, Hyaline    5 (10%)      3 (6%)       4 (8%)                                             
      Respiratory Epithelium, Hyperplasia              1 (2%)                    1 (2%)                                             
      Respiratory Epithelium, Metaplasia, Squamous                                            1 (2%)                                
   Pleura                                             (50)         (50)         (50)         (49)                                   
      Fibrosis                                         1 (2%)                                                                       
      Infiltration Cellular, Lymphoid                                                         1 (2%)                                
   Trachea                                            (50)         (50)         (50)         (50)                                   
      Glands, Degeneration, Cystic                                               1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (50)         (48)         (49)         (49)                                   
      Atrophy                                                                    1 (2%)                                             
      Inflammation, Chronic                            1 (2%)                                                                       
      Anterior Chamber, Hemorrhage                                               1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    6                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Ciliary Body, Inflammation                                    1 (2%)                                                          
      Cornea, Inflammation                             1 (2%)                                                                       
      Lens, Cataract                                   1 (2%)       3 (6%)       4 (8%)       1 (2%)                                
   Harderian Gland                                    (50)         (50)         (50)         (50)                                   
      Inflammation, Suppurative                        1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (49)         (50)                                   
      Cyst                                                                       1 (2%)                                             
      Nephropathy, Chronic                            19 (38%)     21 (42%)     19 (39%)     10 (20%)                               
      Bilateral, Cortex, Renal Tubule, Degeneration                                           1 (2%)                                
      Cortex, Infarct                                                                         2 (4%)                                
      Cortex, Renal Tubule, Accumulation, Hyaline                                                                                   
        Droplet                                                                               1 (2%)                                
      Cortex, Renal Tubule, Hyperplasia                1 (2%)       1 (2%)                                                          
      Medulla, Renal Tubule, Degeneration                                                     1 (2%)                                
      Pelvis, Transitional Epithelium, Hyperplasia     1 (2%)                                 1 (2%)                                
      Pelvis, Transitional Epithelium,                                                                                              
        Mineralization                                 1 (2%)                                                                       
      Renal Tubule, Dilatation                         1 (2%)                                                                       
   Urinary Bladder                                    (50)         (50)         (49)         (49)                                   
      Transitional Epithelium, Hyperplasia             1 (2%)                                                                       
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page    7                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                15            9           12           13                                     
    Natural Death                                      4            6            6            5                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                31           35           31           32                                     
    Natural Death                                                                1                                                  
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (50)         (50)         (50)         (50)                                   
      Foreign Body                                                                            1 (2%)                                
   Intestine Small, Jejunum                           (46)         (47)         (47)         (46)                                   
      Necrosis                                                      1 (2%)                                                          
   Intestine Small, Ileum                             (46)         (47)         (45)         (46)                                   
      Dilatation                                                    1 (2%)                                                          
   Liver                                              (50)         (49)         (50)         (50)                                   
      Angiectasis                                                                1 (2%)       1 (2%)                                
      Clear Cell Focus                                 2 (4%)       5 (10%)      1 (2%)       1 (2%)                                
      Hemorrhage                                       1 (2%)                                                                       
      Hepatodiaphragmatic Nodule                       2 (4%)       2 (4%)       4 (8%)       8 (16%)                               
      Inflammation, Granulomatous                                   1 (2%)                                                          
      Necrosis                                         1 (2%)       1 (2%)       3 (6%)       2 (4%)                                
      Vacuolization Cytoplasmic                        1 (2%)       2 (4%)       3 (6%)       3 (6%)                                
      Bile Duct, Hyperplasia                                                     3 (6%)                                             
      Hepatocyte, Regeneration                                                   1 (2%)                                             
      Periportal, Inflammation, Chronic                                          2 (4%)                                             
      Serosa, Fibrosis                                              1 (2%)                    1 (2%)                                
      Serosa, Hemorrhage                                                                      1 (2%)                                
   Mesentery                                          (12)         (13)         (18)         (11)                                   
      Necrosis                                         7 (58%)     13 (100%)    18 (100%)     9 (82%)                               
      Fat, Hemorrhage                                                                         1 (9%)                                
   Oral Mucosa                                        (1)                       (1)          (4)                                    
      Gingival, Cyst                                                                          1 (25%)                               
      Gingival, Hyperplasia, Squamous                  1 (100%)                                                                     
   Pancreas                                           (50)         (49)         (50)         (50)                                   
      Thrombosis                                                                 1 (2%)                                             
      Acinus, Atrophy                                 15 (30%)     18 (37%)     27 (54%)     21 (42%)                               
      Acinus, Hyperplasia                                                        1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    8                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Acinus, Inflammation                                          1 (2%)                                                          
      Duct, Cyst                                       1 (2%)       2 (4%)       3 (6%)                                             
   Stomach, Forestomach                               (50)         (48)         (50)         (50)                                   
      Diverticulum                                                  1 (2%)                                                          
      Hyperplasia, Squamous                            1 (2%)                                                                       
      Inflammation, Suppurative                                     1 (2%)                                                          
      Ulcer                                            4 (8%)       1 (2%)       1 (2%)                                             
   Stomach, Glandular                                 (50)         (48)         (50)         (49)                                   
      Erosion                                                       2 (4%)       2 (4%)       2 (4%)                                
      Ulcer                                            1 (2%)       2 (4%)       1 (2%)                                             
      Epithelium, Hyperplasia                                                                 1 (2%)                                
   Tongue                                             (1)          (1)                                                              
      Epithelium, Hyperplasia                                       1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (50)         (50)         (50)         (50)                                   
      Thrombosis                                       1 (2%)                                                                       
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                   7 (14%)      5 (10%)      1 (2%)       1 (2%)                                
      Atrium, Thrombosis                               2 (4%)       1 (2%)       2 (4%)       1 (2%)                                
      Pericardium, Inflammation                                                  1 (2%)                                             
      Pericardium, Pigmentation                                                  1 (2%)                                             
      Pericardium, Epicardium, Infiltration                                                                                         
        Cellular, Histiocyte                                        1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Hyperplasia                                      1 (2%)                                 2 (4%)                                
      Necrosis                                                      2 (4%)                                                          
      Vacuolization Cytoplasmic                        8 (16%)      8 (16%)      7 (14%)      6 (12%)                               
   Adrenal Medulla                                    (50)         (50)         (50)         (50)                                   
      Hyperplasia                                     12 (24%)     13 (26%)      8 (16%)     14 (28%)                               
      Bilateral, Hyperplasia                                                                  1 (2%)                                
   Islets, Pancreatic                                 (50)         (48)         (50)         (50)                                   
      Hyperplasia                                      1 (2%)       1 (2%)       2 (4%)       2 (4%)                                
   Parathyroid Gland                                  (46)         (48)         (49)         (47)                                   
      Hyperplasia                                      1 (2%)       1 (2%)                                                          
   Pituitary Gland                                    (50)         (50)         (50)         (49)                                   
      Cyst                                             1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    9                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Hemorrhage                                       1 (2%)                                 1 (2%)                                
      Pars Distalis, Hematocyst                                     1 (2%)                                                          
      Pars Distalis, Hyperplasia                       5 (10%)      8 (16%)      9 (18%)      8 (16%)                               
   Thyroid Gland                                      (50)         (50)         (50)         (49)                                   
      C-Cell, Hyperplasia                              2 (4%)       4 (8%)       9 (18%)      7 (14%)                               
      Follicular Cell, Hyperplasia                                  2 (4%)       2 (4%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Penis                                                                        (2)                                                 
      Inflammation                                                               1 (50%)                                            
   Preputial Gland                                    (48)         (50)         (50)         (49)                                   
      Cyst                                             1 (2%)       1 (2%)       2 (4%)       1 (2%)                                
      Hyperplasia                                      1 (2%)       4 (8%)       1 (2%)       1 (2%)                                
   Prostate                                           (50)         (50)         (50)         (50)                                   
      Hyperplasia                                                                1 (2%)                                             
      Inflammation, Suppurative                        5 (10%)      1 (2%)       4 (8%)       2 (4%)                                
   Seminal Vesicle                                    (50)         (49)         (50)         (50)                                   
      Dilatation                                                                              1 (2%)                                
      Hyperplasia                                                   1 (2%)                                                          
      Inflammation, Suppurative                        1 (2%)                                                                       
   Testes                                             (50)         (50)         (50)         (50)                                   
      Artery, Inflammation, Chronic Active                                       2 (4%)                                             
      Germinal Epithelium, Atrophy                    16 (32%)     12 (24%)     11 (22%)      9 (18%)                               
      Interstitial Cell, Hyperplasia                   7 (14%)      6 (12%)      2 (4%)       3 (6%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Lymph Node                                         (11)         (5)          (11)         (6)                                    
      Deep Cervical, Angiectasis                       1 (9%)                                 1 (17%)                               
      Deep Cervical, Cyst                                           1 (20%)                                                         
      Deep Cervical, Hemorrhage                                                  1 (9%)                                             
      Deep Cervical, Hyperplasia, Lymphoid             1 (9%)                                                                       
      Pancreatic, Ectasia                                                        1 (9%)                                             
      Pancreatic, Hemorrhage                                                                  1 (17%)                               
      Pancreatic, Infiltration Cellular, Histiocyte                              1 (9%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   10                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
   Lymph Node, Bronchial                              (7)          (6)          (12)         (5)                                    
      Hemorrhage                                                                              1 (20%)                               
      Infiltration Cellular                                                                   1 (20%)                               
      Pigmentation                                                                            1 (20%)                               
   Lymph Node, Mesenteric                             (49)         (49)         (50)         (50)                                   
      Angiectasis                                      1 (2%)                                                                       
      Ectasia                                                       1 (2%)                                                          
      Hemorrhage                                                                              1 (2%)                                
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
      Infiltration Cellular, Histiocyte                1 (2%)                    1 (2%)       3 (6%)                                
   Lymph Node, Mediastinal                            (19)         (23)         (25)         (38)                                   
      Angiectasis                                                                             1 (3%)                                
      Hyperplasia, Lymphoid                                                                   1 (3%)                                
   Spleen                                             (50)         (49)         (50)         (50)                                   
      Accessory Spleen                                              3 (6%)                    1 (2%)                                
      Fibrosis                                         2 (4%)       6 (12%)      4 (8%)       1 (2%)                                
      Hematopoietic Cell Proliferation                                                        1 (2%)                                
      Hemorrhage                                                    2 (4%)       1 (2%)       1 (2%)                                
      Hyperplasia, Focal, Lymphoid                                  1 (2%)                                                          
      Necrosis                                         3 (6%)       1 (2%)       1 (2%)       1 (2%)                                
      Lymphocyte, Hyperplasia, Diffuse                 1 (2%)                                                                       
   Thymus                                             (48)         (44)         (46)         (42)                                   
      Hemorrhage                                                                 1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (35)         (43)         (47)         (48)                                   
      Galactocele                                      3 (9%)       2 (5%)       6 (13%)      3 (6%)                                
   Skin                                               (50)         (50)         (50)         (50)                                   
      Cyst Epithelial Inclusion                        4 (8%)       1 (2%)       3 (6%)       2 (4%)                                
      Hyperkeratosis                                   2 (4%)       1 (2%)       2 (4%)                                             
      Inflammation, Acute                                                        2 (4%)                                             
      Inflammation, Granulomatous                                                             1 (2%)                                
      Ulcer                                                                      2 (4%)                                             
      Subcutaneous Tissue, Thrombosis                                            1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Hyperostosis                                                               1 (2%)                                             
      Cartilage, Femur, Hyperplasia                    1 (2%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   11                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
MUSCULOSKELETAL SYSTEM - CONT                                                                                                       
      Femur, Fracture                                               1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (49)         (50)         (50)         (50)                                   
      Compression                                     10 (20%)      5 (10%)      8 (16%)      6 (12%)                               
      Gliosis                                                                                 1 (2%)                                
      Hemorrhage                                                    1 (2%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (49)         (49)         (50)         (49)                                   
      Foreign Body                                     1 (2%)       2 (4%)       3 (6%)       2 (4%)                                
      Inflammation, Suppurative                                     1 (2%)       1 (2%)       1 (2%)                                
      Epiglottis, Metaplasia, Squamous                                           1 (2%)       1 (2%)                                
   Lung                                               (50)         (50)         (50)         (50)                                   
      Congestion                                                                              1 (2%)                                
      Hemorrhage                                       2 (4%)       1 (2%)       4 (8%)       4 (8%)                                
      Inflammation, Chronic                                                      1 (2%)                                             
      Inflammation, Chronic, Diffuse                                             1 (2%)                                             
      Inflammation, Chronic, Focal                     4 (8%)       4 (8%)       5 (10%)     14 (28%)                               
      Inflammation, Suppurative                        1 (2%)                                                                       
      Necrosis                                         1 (2%)                    1 (2%)                                             
      Thrombosis                                       1 (2%)                                                                       
      Alveolar Epithelium, Hyperplasia                 4 (8%)       8 (16%)      6 (12%)      6 (12%)                               
      Alveolar Epithelium, Hypertrophy                              1 (2%)       1 (2%)       2 (4%)                                
      Alveolus, Hypertrophy                                                                   1 (2%)                                
      Alveolus, Infiltration Cellular, Focal,                                                                                       
        Histiocyte                                     9 (18%)     12 (24%)     11 (22%)      4 (8%)                                
      Interstitium, Fibrosis                           1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Mediastinum, Abscess                             1 (2%)                                                                       
      Mediastinum, Inflammation, Chronic                                         1 (2%)                                             
      Mediastinum, Pigmentation                                                  1 (2%)                                             
      Perivascular, Edema                                                                     1 (2%)                                
      Perivascular, Infiltration Cellular,                                                                                          
        Eosinophil                                                                            1 (2%)                                
   Nose                                               (50)         (48)         (50)         (49)                                   
      Foreign Body                                     5 (10%)      1 (2%)       3 (6%)                                             
      Inflammation, Suppurative                        5 (10%)      9 (19%)     17 (34%)     10 (20%)                               
      Glands, Dilatation                               3 (6%)      30 (63%)     48 (96%)     46 (94%)                               
      Goblet Cell, Hyperplasia                         1 (2%)       3 (6%)       7 (14%)     16 (33%)                               
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   12                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Nasolacrimal Duct, Inflammation, Suppurative     2 (4%)       6 (13%)      1 (2%)       4 (8%)                                
      Nasopharyngeal Duct, Cyst                                                               1 (2%)                                
      Nasopharyngeal Duct, Foreign Body                                                       1 (2%)                                
      Nasopharyngeal Duct, Inflammation,                                                                                            
        Suppurative                                                              1 (2%)                                             
      Nasopharyngeal Duct, Respiratory Epithelium,                                                                                  
         Hyperplasia                                                                          1 (2%)                                
      Olfactory Epithelium, Degeneration                           47 (98%)     49 (98%)     49 (100%)                              
      Olfactory Epithelium, Degeneration, Hyaline      4 (8%)                    2 (4%)       1 (2%)                                
      Olfactory Epithelium, Hyperplasia, Basal Cell                21 (44%)     44 (88%)     48 (98%)                               
      Olfactory Epithelium, Metaplasia                              1 (2%)                    2 (4%)                                
      Respiratory Epithelium, Hyperplasia              1 (2%)                                                                       
      Turbinate, Cyst                                               1 (2%)                                                          
   Pleura                                             (50)         (50)         (50)         (50)                                   
      Mesothelium, Hyperplasia                                                   1 (2%)                                             
   Trachea                                            (50)         (49)         (50)         (49)                                   
      Glands, Degeneration, Cystic                     1 (2%)                                 5 (10%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (50)         (48)         (48)         (49)                                   
      Anterior Chamber, Hemorrhage                                               1 (2%)                                             
      Cornea, Mineralization                                                                  1 (2%)                                
      Lens, Cataract                                   2 (4%)       1 (2%)       3 (6%)       1 (2%)                                
      Retina, Atrophy                                               1 (2%)                                                          
   Harderian Gland                                    (50)         (50)         (50)         (50)                                   
      Atrophy                                                                    1 (2%)                                             
   Zymbal's Gland                                     (1)                       (3)                                                 
      Inflammation, Suppurative                                                  1 (33%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (49)         (50)         (49)                                   
      Cyst                                                          1 (2%)                    1 (2%)                                
      Nephropathy, Chronic                            37 (74%)     41 (84%)     41 (82%)     45 (92%)                               
      Cortex, Infarct                                  1 (2%)       1 (2%)                                                          
      Cortex, Renal Tubule, Degeneration                                                      1 (2%)                                
      Cortex, Renal Tubule, Hyperplasia                1 (2%)       2 (4%)                    2 (4%)                                
      Cortex, Renal Tubule, Hypertrophy                1 (2%)                                                                       
      Medulla, Infarct                                              1 (2%)                                                          
      Medulla, Infiltration Cellular, Lipocyte                      1 (2%)                                                          
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   13                                                              
                                                                                                                                   
NTP Experiment-Test: 88004-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           DIVINYLBENZENE                                      Date: 12/17/03    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:35:06    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     CONTROL      100 PPM      200 PPM      400 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Papilla, Renal Tubule, Dilatation                                                       1 (2%)                                
      Pelvis, Transitional Epithelium, Hyperplasia     1 (2%)       1 (2%)                                                          
      Pelvis, Transitional Epithelium,                                                                                              
        Mineralization                                                                        1 (2%)                                
   Urethra                                                                      (1)                                                 
      Transitional Epithelium, Hyperplasia                                       1 (100%)                                           
   Urinary Bladder                                    (50)         (49)         (50)         (49)                                   
      Calculus Micro Observation Only                  4 (8%)       2 (4%)       4 (8%)       4 (8%)                                
      Hemorrhage                                       2 (4%)       1 (2%)       1 (2%)                                             
      Transitional Epithelium, Hyperplasia                                       1 (2%)                                             
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   14                                                              
                                                                                                                                   
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                             ----------              END OF REPORT             ----------                                           
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NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.