National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/2133

TDMS Study 05075-01 Pathology Tables


                                     INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)
                                                         DIPHENYLHYDANTOIN


NTP Experiment-Test: 05075-01                                                                                     Report: PEIRPT03
Study Type: CHRONIC                                                                                               Date: 09/09/94
Route: DOSED FEED                                                                                                 Time: 09:05:49




       Facility:  Battelle Columbus Laboratory

       Chemical CAS #:  57-41-0

       Lock Date:  None

       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: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1          0-3          3-3          10-3           
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           50           50           50           50           
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                17           19           19            9           19           15           
    Natural Death                                      2            2            4            4            2            2           
  Survivors                                                                                                                         
    Terminal Sacrifice                                31           29           27           37           28           33           
    Moribund Sacrifice                                                                                     1                        
  Animals Examined Microscopically                    50           50           50           50           50           50           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (48)         (20)         (20)         (9)          (19)         (16)         
      Edema                                                         1 (5%)                                                          
      Inflammation, Chronic Active, Focal              1 (2%)                                                                       
      Ulcer                                            1 (2%)                    1 (5%)                                             
      Submucosa, Edema                                 1 (2%)                    1 (5%)                                             
   Intestine Large, Colon                             (49)         (20)         (20)         (10)         (20)         (16)         
      Parasite Metazoan                                1 (2%)                    1 (5%)                                 1 (6%)      
   Intestine Large, Rectum                            (49)         (20)         (20)         (9)          (20)         (16)         
      Parasite Metazoan                                2 (4%)                                                                       
   Liver                                              (50)         (49)         (50)         (50)         (50)         (50)         
      Basophilic Focus                                40 (80%)     35 (71%)     30 (60%)     33 (66%)     35 (70%)     31 (62%)     
      Clear Cell Focus                                 1 (2%)       2 (4%)                                 1 (2%)       1 (2%)      
      Cyst                                                          1 (2%)       1 (2%)       1 (2%)                                
      Eosinophilic Focus                                                                      3 (6%)       1 (2%)       1 (2%)      
      Fatty Change                                     5 (10%)      3 (6%)       3 (6%)                    1 (2%)       2 (4%)      
      Fatty Change, Diffuse                                                      2 (4%)                                             
      Granuloma, Multiple                                           1 (2%)                                                          
      Hepatodiaphragmatic Nodule                                    1 (2%)       1 (2%)                                             
      Mixed Cell Focus                                 1 (2%)                    1 (2%)       1 (2%)                    2 (4%)      
      Necrosis, Coagulative, Focal                                                                         1 (2%)                   
      Necrosis, Coagulative, Multifocal                1 (2%)       2 (4%)                    1 (2%)       1 (2%)       1 (2%)      
      Necrosis, Caseous                                             1 (2%)                                                          
      Necrosis, Caseous, Multifocal                                                           1 (2%)       1 (2%)                   
      Regeneration, Focal                              2 (4%)       1 (2%)       2 (4%)                                 1 (2%)      
      Centrilobular, Cytomegaly                                                  7 (14%)     22 (44%)     24 (48%)     29 (58%)     
      Sinusoid, Angiectasis                            3 (6%)       1 (2%)                                                          
      Sinusoid, Angiectasis, Multifocal                             1 (2%)                                                          
   Mesentery                                          (3)          (6)          (3)          (1)          (1)          (2)          
      Inflammation, Chronic                            1 (33%)      1 (17%)                                                         
      Artery, Inflammation, Chronic                    1 (33%)                                                                      
      Fat, Necrosis                                    1 (33%)      3 (50%)      3 (100%)     1 (100%)                  1 (50%)     
   Pancreas                                           (50)         (20)         (23)         (10)         (21)         (16)         
      Fibrosis, Focal                                                            1 (4%)                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    2                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1          0-3          3-3          10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Acinus, Atrophy                                 21 (42%)      7 (35%)     13 (57%)      5 (50%)      5 (24%)      5 (31%)     
   Salivary Glands                                    (50)         (21)         (22)         (12)         (22)         (17)         
      Ectopic Tissue                                                                                       1 (5%)                   
      Acinus, Parotid Gland, Atrophy                   1 (2%)                                                                       
      Parotid Gland, Inflammation, Chronic                                                                              1 (6%)      
   Stomach, Forestomach                               (49)         (20)         (23)         (11)         (22)         (16)         
      Edema                                                                                                             1 (6%)      
      Inflammation, Chronic                                                                                1 (5%)                   
      Epithelium, Acanthosis, Diffuse                                                                      1 (5%)                   
      Epithelium, Hyperkeratosis, Diffuse                                                                  1 (5%)                   
      Submucosa, Edema                                 1 (2%)                                                                       
   Stomach, Glandular                                 (49)         (20)         (20)         (11)         (20)         (16)         
      Inflammation, Chronic                                                                                1 (5%)                   
      Inflammation, Subacute                                        1 (5%)       1 (5%)                                             
      Ulcer                                                                                   1 (9%)                                
      Mucosa, Inflammation, Multifocal, Necrotizing                                                        1 (5%)                   
      Mucosa, Proliferation, Focal                                  1 (5%)                                                          
   Tooth                                                                        (1)                                                 
      Gingiva, Inflammation, Chronic                                             1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (1)                                                                           
      Aorta, Inflammation, Chronic, Focal              1 (100%)                                                                     
   Heart                                              (50)         (21)         (24)         (13)         (22)         (17)         
      Autolysis                                                                  1 (4%)                                             
      Coronary Artery, Inflammation, Chronic           1 (2%)                    1 (4%)                                 1 (6%)      
      Myocardium, Degeneration, Diffuse                                                                    1 (5%)                   
      Myocardium, Degeneration, Multifocal            32 (64%)     13 (62%)     13 (54%)      6 (46%)      8 (36%)      5 (29%)     
      Myocardium, Fibrosis, Focal                      1 (2%)                                                                       
      Myocardium, Inflammation, Chronic, Multifocal    2 (4%)                    1 (4%)                                             
      Valve, Inflammation, Chronic                                               1 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (50)         (21)         (23)         (13)         (20)         (17)         
      Atrophy                                                                                                           1 (6%)      
      Atypia Cellular, Focal                           1 (2%)                                                                       
      Congestion                                       1 (2%)                                                                       
      Hyperplasia, Nodular                            19 (38%)      3 (14%)      7 (30%)      1 (8%)       9 (45%)      5 (29%)     
      Hypertrophy, Focal                               3 (6%)       1 (5%)                                              2 (12%)     
      Hypertrophy, Multifocal                                                                              1 (5%)                   
      Necrosis, Coagulative                                                                                1 (5%)                   
      Vacuolization Cytoplasmic, Focal                              1 (5%)                    2 (15%)                   1 (6%)      
   Adrenal Gland, Medulla                             (49)         (21)         (23)         (13)         (22)         (17)         
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    3                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1          0-3          3-3          10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Hyperplasia, Nodular                             4 (8%)       3 (14%)      6 (26%)                   7 (32%)      4 (24%)     
      Necrosis, Coagulative                                                                                1 (5%)                   
      Vacuolization Cytoplasmic, Focal                                                                     1 (5%)                   
   Parathyroid Gland                                  (45)         (18)         (21)         (12)         (19)         (17)         
      Hyperplasia, Diffuse                             1 (2%)                    1 (5%)                    1 (5%)                   
      Hyperplasia, Nodular                             1 (2%)                                                                       
   Pituitary Gland                                    (50)         (41)         (43)         (32)         (35)         (33)         
      Angiectasis, Focal                                                                      1 (3%)                                
      Autolysis                                                                               1 (3%)                                
      Pars Distalis, Angiectasis, Focal                             2 (5%)       5 (12%)      2 (6%)       4 (11%)      6 (18%)     
      Pars Distalis, Angiectasis, Multifocal                                     1 (2%)                                             
      Pars Distalis, Cyst                              3 (6%)       4 (10%)      5 (12%)      6 (19%)      2 (6%)       5 (15%)     
      Pars Distalis, Hyperplasia, Nodular              4 (8%)       3 (7%)       7 (16%)      3 (9%)       6 (17%)      2 (6%)      
      Pars Intermedia, Cyst                                                                                             1 (3%)      
   Thyroid Gland                                      (48)         (20)         (19)         (9)          (20)         (17)         
      Cyst                                                                                                 1 (5%)                   
      C-Cell, Hyperplasia                             33 (69%)     14 (70%)     14 (74%)      8 (89%)     16 (80%)     16 (94%)     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (45)         (21)         (24)         (14)         (24)         (20)         
      Autolysis                                                                  1 (4%)                                             
      Hyperplasia                                      2 (4%)       2 (10%)                                                         
      Inflammation, Chronic                            6 (13%)      4 (19%)      4 (17%)      4 (29%)      2 (8%)       4 (20%)     
      Inflammation, Chronic Active                     3 (7%)       2 (10%)                                             1 (5%)      
      Duct, Dilatation                                 1 (2%)       1 (5%)       2 (8%)       3 (21%)      1 (4%)       2 (10%)     
   Ovary                                              (49)         (23)         (26)         (19)         (26)         (21)         
      Inflammation, Chronic                            5 (10%)      1 (4%)                    1 (5%)                                
      Bilateral, Periovarian Tissue, Cyst                                                                  1 (4%)                   
      Corpus Luteum, Congestion                        1 (2%)                                                                       
      Follicle, Cyst                                   1 (2%)       1 (4%)                                                          
      Periovarian Tissue, Cyst                         5 (10%)      4 (17%)      5 (19%)      7 (37%)      4 (15%)      5 (24%)     
      Periovarian Tissue, Necrosis, Caseous                                                                             1 (5%)      
      Vein, Congestion                                                                                                  1 (5%)      
   Uterus                                             (50)         (26)         (26)         (25)         (35)         (31)         
      Dilatation                                                    2 (8%)       1 (4%)       3 (12%)      2 (6%)       1 (3%)      
      Hemorrhage                                                                                           1 (3%)                   
      Hyperplasia                                                                1 (4%)                                             
      Hyperplasia, Cystic                                                                                               1 (3%)      
      Prolapse                                         3 (6%)                    1 (4%)                                             
      Cervix, Inflammation, Suppurative                                          1 (4%)                    2 (6%)       5 (16%)     
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    4                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1          0-3          3-3          10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Endometrium, Bacterium                           1 (2%)                                                                       
      Endometrium, Hyperplasia, Cystic                 9 (18%)      2 (8%)                    5 (20%)      6 (17%)      2 (6%)      
      Endometrium, Hyperplasia, Nodular                                                                    1 (3%)                   
      Endometrium, Necrosis, Coagulative               1 (2%)                                                           1 (3%)      
      Lumen, Hemorrhage                                                                                    1 (3%)                   
      Wall, Bacterium                                                            1 (4%)                                             
      Wall, Cyst                                                                              1 (4%)                                
      Wall, Inflammation, Chronic Active               2 (4%)                                                                       
      Wall, Inflammation, Necrotizing                  1 (2%)                    1 (4%)                                             
   Vagina                                             (2)                       (1)          (2)          (4)          (7)          
      Cyst                                                                       1 (100%)     1 (50%)      4 (100%)     7 (100%)    
      Lamina Propria, Inflammation, Necrotizing        1 (50%)                                                                      
      Lumen, Exudate                                                                          1 (50%)                               
      Wall, Edema                                      1 (50%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Blood                                              (1)                                                                           
      Polychromasia                                    1 (100%)                                                                     
   Bone Marrow                                        (50)         (21)         (22)         (12)         (22)         (17)         
      Femoral, Angiectasis                             1 (2%)                                                                       
      Femoral, Hyperplasia                             7 (14%)      8 (38%)     11 (50%)      4 (33%)     14 (64%)      8 (47%)     
      Femoral, Hyperplasia, Re Cell                    1 (2%)                                                                       
      Femoral, Hypoplasia                              2 (4%)                                                                       
      Femoral, Myelofibrosis                                                                  1 (8%)                    2 (12%)     
   Lymph Node                                         (49)         (21)         (26)         (12)         (23)         (22)         
      Mandibular, Hemorrhage, Focal                                                                        1 (4%)                   
      Mandibular, Infiltration Cellular,                                                                                            
          Polymorphonuclear                                                                                             1 (5%)      
      Mandibular, Infiltration Cellular, Histiocyte                 1 (5%)                                                          
      Mandibular, Inflammation, Chronic                                          1 (4%)                                             
      Mediastinal, Pigmentation, Hemosiderin                                     1 (4%)                                             
      Renal, Necrosis, Caseous                                                                                          1 (5%)      
      Sinus, Ectasia                                                             1 (4%)                                             
      Sinus, Mandibular, Ectasia                                                                           2 (9%)       1 (5%)      
   Lymph Node, Mesenteric                             (1)          (1)          (4)          (1)          (6)          (6)          
      Sinus, Ectasia                                                             1 (25%)                   1 (17%)      3 (50%)     
   Spleen                                             (50)         (26)         (29)         (17)         (22)         (21)         
      Autolysis                                                                               1 (6%)                                
      Fibrosis, Diffuse                                                                       1 (6%)                                
      Fibrosis, Focal                                                            1 (3%)                                             
      Granuloma, Single                                1 (2%)                                                                       
      Hematopoietic Cell Proliferation                 3 (6%)       2 (8%)       1 (3%)       1 (6%)       1 (5%)       1 (5%)      
      Necrosis, Coagulative                            1 (2%)                    1 (3%)                                 1 (5%)      
      Capsule, Cyst                                                                           1 (6%)                                
      Capsule, Hemorrhage                                           1 (4%)                                                          
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    5                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1          0-3          3-3          10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Capsule, Inflammation, Focal, Subacute                                     1 (3%)                                             
   Thymus                                             (46)         (18)         (21)         (12)         (19)         (17)         
      Hemorrhage, Multifocal                                                     1 (5%)                                             
      Arteriole, Inflammation, Chronic                 1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (24)         (31)         (19)         (25)         (23)         
      Hyperplasia, Cystic                             32 (64%)     15 (63%)     12 (39%)      6 (32%)     15 (60%)     12 (52%)     
      Duct, Inflammation, Chronic Active               1 (2%)                                                                       
   Skin                                               (50)         (22)         (23)         (14)         (26)         (18)         
      Acanthosis                                       1 (2%)       1 (5%)                                 1 (4%)       1 (6%)      
      Hyperkeratosis                                   1 (2%)       1 (5%)                                 1 (4%)       1 (6%)      
      Inflammation, Chronic                            1 (2%)       1 (5%)                                                          
      Inflammation, Necrotizing                                     1 (5%)                                                          
      Tail, Acanthosis, Focal                                                                              1 (4%)                   
      Tail, Hyperkeratosis, Focal                                                                          1 (4%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (21)         (24)         (13)         (22)         (17)         
      Hyperostosis                                     1 (2%)                                                                       
      Femur, Osteopetrosis                             2 (4%)                                 1 (8%)                                
      Tibia, Proliferation                                                       1 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (21)         (23)         (13)         (22)         (17)         
      Infarct                                                       1 (5%)       1 (4%)                                             
      Infarct, Multiple                                                          1 (4%)                                             
      Inflammation, Multifocal, Necrotizing                         1 (5%)                                                          
      Hypothalamus, Compression                       15 (30%)      8 (38%)      5 (22%)      4 (31%)      4 (18%)      5 (29%)     
      Hypothalamus, Hemorrhage, Multifocal                                       1 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (22)         (24)         (13)         (23)         (18)         
      Congestion                                       1 (2%)                                              1 (4%)                   
      Alveolar Epithelium, Hyperplasia                 1 (2%)                                                                       
      Alveolus, Hemorrhage                                          3 (14%)                                             1 (6%)      
      Alveolus, Hemorrhage, Multifocal                                           2 (8%)                                             
      Alveolus, Inflammation, Multifocal,                                                                                           
          Suppurative                                                                         1 (8%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    6                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1          0-3          3-3          10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Bronchus, Foreign Body                           1 (2%)                                 1 (8%)                                
      Bronchus, Inflammation, Multifocal,                                                                                           
          Suppurative                                                                         1 (8%)                                
      Interstitium, Inflammation, Chronic, Focal       3 (6%)       2 (9%)                                                          
      Interstitium, Inflammation, Chronic,                                                                                          
          Multifocal                                                             1 (4%)       2 (15%)      1 (4%)                   
   Nose                                               (50)         (21)         (23)         (13)         (22)         (17)         
      Nares, Inflammation, Chronic Active                                                                  1 (5%)                   
      Sinus, Inflammation, Chronic Active                           1 (5%)                                                          
   Trachea                                            (50)         (21)         (22)         (12)         (22)         (17)         
      Inflammation, Subacute                                                                                            1 (6%)      
      Lamina Propria, Inflammation, Chronic            1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Ear                                                (3)                                    (1)          (1)          (1)          
      Middle Ear, Inflammation, Chronic Active                                                                          1 (100%)    
   Eye                                                (9)          (6)          (6)          (7)          (7)          (9)          
      Anterior, Synechia                                                                                   1 (14%)                  
      Bilateral, Lens Crystalline, Cataract                                                                             1 (11%)     
      Cornea, Inflammation, Suppurative                                                       1 (14%)                               
      Lens Crystalline, Cataract                       7 (78%)      5 (83%)      6 (100%)     6 (86%)      4 (57%)      8 (89%)     
      Lids, Inflammation, Suppurative                  1 (11%)                                                                      
      Posterior Chamber, Inflammation, Chronic                      3 (50%)      4 (67%)      4 (57%)      5 (71%)      8 (89%)     
      Retina, Atrophy                                  7 (78%)      2 (33%)      3 (50%)      1 (14%)      1 (14%)                  
      Sclera, Mineralization, Multifocal                            1 (17%)                                1 (14%)                  
   Harderian Gland                                    (3)          (1)          (3)          (1)          (1)                       
      Inflammation, Chronic, Multifocal                2 (67%)                   2 (67%)      1 (100%)     1 (100%)                 
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (21)         (23)         (13)         (22)         (17)         
      Hydronephrosis                                   1 (2%)                                                                       
      Inflammation, Multifocal, Necrotizing            1 (2%)       1 (5%)                                                          
      Nephropathy, Multifocal                         32 (64%)     11 (52%)     10 (43%)      5 (38%)      9 (41%)      6 (35%)     
      Thrombosis                                                                              1 (8%)                                
      Glomerulus, Inflammation,                                                                                                     
          Membranoproliferative                                                                            1 (5%)                   
      Papilla, Bacterium                                            1 (5%)                                                          
      Pelvis, Renal Tubule, Bacterium                  1 (2%)                                                                       
   Urinary Bladder                                    (50)         (21)         (20)         (11)         (20)         (16)         
      Ectasia                                                                                                           1 (6%)      
      Inflammation, Acute                                           1 (5%)                                                          
      Inflammation, Chronic                                         1 (5%)                                                          
      Lumen, Hemorrhage                                1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    7                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1          0-3          3-3          10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Mucosa, Hyperplasia, Papillary                                1 (5%)                                                          
      Transitional Epithelium, Hyperplasia, Diffuse    1 (2%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    8                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   2400 PPM     2400 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50                                                               
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                11           13                                                               
    Natural Death                                      1            1                                                               
    Drowned                                                         5                                                               
  Survivors                                                                                                                         
    Terminal Sacrifice                                37           31                                                               
    Moribund Sacrifice                                 1                                                                            
  Animals Examined Microscopically                    50           50                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (50)         (49)                                                             
      Ulcer                                                         1 (2%)                                                          
   Intestine Large, Colon                             (50)         (50)                                                             
      Dilatation                                                    1 (2%)                                                          
      Inflammation, Chronic, Focal                                  2 (4%)                                                          
      Parasite Metazoan                                3 (6%)       3 (6%)                                                          
   Intestine Small, Ileum                             (48)         (50)                                                             
      Inflammation, Chronic Active, Focal              1 (2%)                                                                       
   Liver                                              (50)         (50)                                                             
      Basophilic Focus                                 6 (12%)      3 (6%)                                                          
      Clear Cell Focus                                 2 (4%)       3 (6%)                                                          
      Eosinophilic Focus                               5 (10%)      2 (4%)                                                          
      Hepatodiaphragmatic Nodule                                    2 (4%)                                                          
      Mixed Cell Focus                                 1 (2%)       4 (8%)                                                          
      Necrosis, Coagulative, Multifocal                1 (2%)                                                                       
      Regeneration, Focal                                           1 (2%)                                                          
      Centrilobular, Cytomegaly                       42 (84%)     38 (76%)                                                         
      Sinusoid, Angiectasis                            1 (2%)                                                                       
   Pancreas                                           (50)         (50)                                                             
      Ectopic Tissue                                                1 (2%)                                                          
      Acinus, Atrophy                                 22 (44%)     14 (28%)                                                         
      Acinus, Hypertrophy, Focal                                    1 (2%)                                                          
   Salivary Glands                                    (49)         (50)                                                             
      Acinus, Parotid Gland, Atrophy                   1 (2%)                                                                       
   Stomach, Forestomach                               (50)         (50)                                                             
      Hyperkeratosis                                   1 (2%)                                                                       
      Inflammation, Subacute                                        1 (2%)                                                          
      Inflammation, Suppurative                        1 (2%)                                                                       
   Stomach, Glandular                                 (50)         (50)                                                             
      Mucosa, Proliferation, Focal                     1 (2%)                                                                       
   Tooth                                              (3)          (1)                                                              
      Dysplasia                                        1 (33%)                                                                      
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    9                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   2400 PPM     2400 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Gingiva, Inflammation, Chronic Active            1 (33%)      1 (100%)                                                        
      Gingiva, Inflammation, Suppurative               1 (33%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)                                                             
      Atrium Left, Thrombosis                          1 (2%)       1 (2%)                                                          
      Coronary Artery, Inflammation, Chronic           1 (2%)       1 (2%)                                                          
      Endocardium, Proliferation                       1 (2%)                                                                       
      Epicardium, Inflammation, Chronic                2 (4%)       2 (4%)                                                          
      Myocardium, Degeneration, Multifocal            27 (54%)     20 (40%)                                                         
      Myocardium, Fibrosis, Focal                      1 (2%)                                                                       
      Myocardium, Inflammation, Chronic, Multifocal                 5 (10%)                                                         
      Valve, Inflammation, Chronic                                  1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (50)         (50)                                                             
      Hyperplasia, Nodular                            22 (44%)     15 (30%)                                                         
      Hypertrophy, Focal                               2 (4%)                                                                       
      Mineralization, Focal                                         1 (2%)                                                          
      Vacuolization Cytoplasmic, Focal                 1 (2%)       1 (2%)                                                          
   Adrenal Gland, Medulla                             (50)         (50)                                                             
      Hyperplasia, Nodular                            18 (36%)     15 (30%)                                                         
   Pituitary Gland                                    (50)         (50)                                                             
      Angiectasis, Focal                               1 (2%)                                                                       
      Pars Distalis, Angiectasis, Focal                3 (6%)       2 (4%)                                                          
      Pars Distalis, Cyst                                           4 (8%)                                                          
      Pars Distalis, Hyperplasia, Nodular             10 (20%)      2 (4%)                                                          
   Thyroid Gland                                      (50)         (49)                                                             
      C-Cell, Hyperplasia                             43 (86%)     39 (80%)                                                         
      Follicle, Dilatation, Focal                      2 (4%)                                                                       
      Follicle, Dilatation, Multifocal                 2 (4%)                                                                       
      Follicle, Hyperplasia, Focal                                  1 (2%)                                                          
      Follicular Cell, Hyperplasia, Focal              1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   10                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   2400 PPM     2400 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (50)         (49)                                                             
      Hyperplasia                                      3 (6%)       1 (2%)                                                          
      Inflammation, Chronic                            7 (14%)      9 (18%)                                                         
      Inflammation, Chronic Active                     4 (8%)       1 (2%)                                                          
      Duct, Dilatation                                              3 (6%)                                                          
   Ovary                                              (50)         (50)                                                             
      Inflammation, Chronic                                         2 (4%)                                                          
      Follicle, Cyst                                   1 (2%)       1 (2%)                                                          
      Periovarian Tissue, Cyst                                      2 (4%)                                                          
   Uterus                                             (50)         (50)                                                             
      Prolapse                                         1 (2%)       1 (2%)                                                          
      Endometrium, Hyperplasia, Cystic                 6 (12%)     10 (20%)                                                         
      Endometrium, Necrosis, Coagulative               2 (4%)       1 (2%)                                                          
      Wall, Bacterium                                               1 (2%)                                                          
      Wall, Inflammation, Chronic Active               2 (4%)       3 (6%)                                                          
   Vagina                                             (2)          (3)                                                              
      Cyst                                             1 (50%)      3 (100%)                                                        
      Prolapse                                         1 (50%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)                                                             
      Femoral, Hyperplasia                             8 (16%)      9 (18%)                                                         
   Lymph Node                                         (49)         (50)                                                             
      Sinus, Mandibular, Ectasia                       3 (6%)                                                                       
   Lymph Node, Mesenteric                             (4)          (3)                                                              
      Sinus, Ectasia                                   1 (25%)      1 (33%)                                                         
   Spleen                                             (50)         (50)                                                             
      Fibrosis, Focal                                  2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (49)                                                             
      Hyperplasia, Cystic                             16 (32%)     21 (43%)                                                         
      Necrosis, Coagulative                                         1 (2%)                                                          
   Skin                                               (50)         (50)                                                             
      Edema                                                         1 (2%)                                                          
      Infiltration Cellular, Polymorphonuclear                      1 (2%)                                                          
      Inflammation, Chronic                                         1 (2%)                                                          
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   11                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   2400 PPM     2400 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)                                                             
      Gliosis, Focal                                   1 (2%)                                                                       
      Infarct                                          1 (2%)                                                                       
      Hypothalamus, Compression                        4 (8%)       2 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)                                                             
      Congestion                                                    3 (6%)                                                          
      Alveolus, Hemorrhage                             2 (4%)                                                                       
      Artery, Mineralization                           1 (2%)       1 (2%)                                                          
      Interstitium, Inflammation, Chronic,                                                                                          
          Multifocal                                   1 (2%)       1 (2%)                                                          
   Trachea                                            (50)         (50)                                                             
      Lamina Propria, Inflammation, Chronic                         2 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Ear                                                             (4)                                                              
      Canal, External Ear, Exudate, Subacute                        1 (25%)                                                         
      Middle Ear, Inflammation, Chronic                             1 (25%)                                                         
      Middle Ear, Inflammation, Chronic Active                      1 (25%)                                                         
      Middle Ear, Inflammation, Subacute                            1 (25%)                                                         
   Eye                                                (8)          (4)                                                              
      Anterior Chamber, Inflammation, Suppurative      1 (13%)                                                                      
      Lens Crystalline, Cataract                       6 (75%)      4 (100%)                                                        
      Posterior Chamber, Inflammation, Chronic         2 (25%)                                                                      
      Retina, Atrophy                                  6 (75%)      3 (75%)                                                         
      Sclera, Mineralization, Multifocal               1 (13%)                                                                      
   Harderian Gland                                    (7)          (2)                                                              
      Inflammation, Chronic, Multifocal                5 (71%)      2 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   12                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   2400 PPM     2400 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)                                                             
      Infarct                                                       1 (2%)                                                          
      Inflammation, Multifocal, Necrotizing                         1 (2%)                                                          
      Nephropathy, Multifocal                         15 (30%)     15 (30%)                                                         
      Pelvis, Renal Tubule, Bacterium                               1 (2%)                                                          
   Urinary Bladder                                    (50)         (50)                                                             
      Inflammation, Acute                                           1 (2%)                                                          
      Inflammation, Chronic                            2 (4%)                                                                       
      Transitional Epithelium, Hyperplasia, Diffuse                 1 (2%)                                                          
      Transitional Epithelium, Hyperplasia, Focal      1 (2%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   13                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1           0-3           3-3        10-3           
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           50           50           50           50           
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                22           21           13           21           24           21           
    Natural Death                                      2            5            4            3            4            6           
  Survivors                                                                                                                         
    Terminal Sacrifice                                25           23           33           26           21           21           
    Moribund Sacrifice                                 1            1                                      1                        
    Natural Death                                                                                                       2           
  Animals Examined Microscopically                    50           50           50           50           50           50           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (49)         (22)         (13)         (22)         (26)         (21)         
      Inflammation, Chronic, Focal                                                            1 (5%)                                
      Arteriole, Inflammation, Chronic                 1 (2%)                                                                       
      Arteriole, Thrombosis                            1 (2%)                                                                       
   Intestine Large, Colon                             (49)         (24)         (14)         (22)         (26)         (23)         
      Diverticulum                                                               1 (7%)                                             
      Parasite Metazoan                                3 (6%)       2 (8%)                                 3 (12%)      2 (9%)      
   Intestine Large, Rectum                            (48)         (24)         (14)         (22)         (26)         (22)         
      Parasite Metazoan                                3 (6%)                                 1 (5%)                                
      Ulcer                                                                                                             1 (5%)      
   Intestine Small, Ileum                             (46)         (22)         (13)         (23)         (26)         (23)         
      Inflammation, Necrotizing                                                               1 (4%)                    1 (4%)      
      Ulcer                                            1 (2%)                                                           1 (4%)      
   Intestine Small, Jejunum                           (48)         (24)         (13)         (22)         (26)         (22)         
      Inflammation, Chronic, Focal                     1 (2%)                                                                       
      Peyer's Patch, Inflammation, Suppurative                                                             1 (4%)                   
   Liver                                              (50)         (50)         (49)         (50)         (49)         (49)         
      Basophilic Focus                                17 (34%)     17 (34%)     24 (49%)     15 (30%)     12 (24%)     26 (53%)     
      Clear Cell Focus                                 2 (4%)       5 (10%)     10 (20%)      8 (16%)      6 (12%)      3 (6%)      
      Congestion                                                                                                        1 (2%)      
      Degeneration, Cystic                             6 (12%)      5 (10%)      9 (18%)      3 (6%)       5 (10%)      2 (4%)      
      Eosinophilic Focus                               5 (10%)      2 (4%)       5 (10%)      6 (12%)      8 (16%)     11 (22%)     
      Fatty Change                                     3 (6%)       1 (2%)       1 (2%)       1 (2%)       3 (6%)       3 (6%)      
      Hepatodiaphragmatic Nodule                                    1 (2%)                                 1 (2%)       1 (2%)      
      Mixed Cell Focus                                 2 (4%)                                              1 (2%)       5 (10%)     
      Necrosis, Coagulative, Focal                                  1 (2%)       2 (4%)                                 1 (2%)      
      Necrosis, Coagulative, Multifocal                4 (8%)       5 (10%)      1 (2%)       1 (2%)                    1 (2%)      
      Necrosis, Caseous, Focal                         1 (2%)                                                                       
      Regeneration, Focal                                                        1 (2%)                    2 (4%)       2 (4%)      
      Regeneration, Multifocal                                                                             1 (2%)                   
      Centrilobular, Cytomegaly                                                 24 (49%)     13 (26%)     14 (29%)     29 (59%)     
      Centrilobular, Hemorrhage                                                               1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   14                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1           0-3           3-3        10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Centrilobular, Necrosis, Coagulative                          1 (2%)       2 (4%)       2 (4%)       1 (2%)                   
      Centrilobular, Necrosis, Caseous                                                        1 (2%)                                
      Periportal, Vacuolization Cytoplasmic                         1 (2%)                                                          
      Sinusoid, Angiectasis                            1 (2%)       4 (8%)       3 (6%)       1 (2%)       3 (6%)       5 (10%)     
      Sinusoid, Angiectasis, Focal                                  1 (2%)       1 (2%)                                             
      Sinusoid, Angiectasis, Multifocal                1 (2%)                                                                       
   Mesentery                                          (7)          (3)          (3)          (3)          (7)          (2)          
      Inflammation, Chronic                            2 (29%)                                                                      
      Fat, Necrosis                                    2 (29%)      2 (67%)                                2 (29%)      1 (50%)     
   Pancreas                                           (50)         (27)         (16)         (23)         (28)         (25)         
      Autolysis                                                     1 (4%)                                                          
      Acinus, Atrophy                                 27 (54%)     14 (52%)     11 (69%)     13 (57%)     17 (61%)     14 (56%)     
      Acinus, Hyperplasia                                                                     1 (4%)                                
      Acinus, Hypertrophy, Focal                                                 1 (6%)                                             
      Artery, Inflammation, Acute                                                                                       1 (4%)      
      Artery, Inflammation, Chronic                    1 (2%)                                 1 (4%)       2 (7%)       2 (8%)      
      Duct, Concretion                                 1 (2%)                                                                       
      Duct, Ectasia                                    1 (2%)       2 (7%)                                 1 (4%)                   
   Salivary Glands                                    (48)         (27)         (16)         (23)         (27)         (28)         
      Autolysis                                                                  1 (6%)                                             
      Acinus, Submandibular Gland, Atrophy             1 (2%)       1 (4%)                                                          
      Parotid Gland, Inflammation, Chronic             1 (2%)                                                                       
   Stomach, Forestomach                               (49)         (26)         (15)         (24)         (27)         (26)         
      Edema                                                         1 (4%)                                                          
      Ulcer                                            2 (4%)       1 (4%)                    2 (8%)       3 (11%)                  
      Epithelium, Acanthosis, Diffuse                                                                                   1 (4%)      
   Stomach, Glandular                                 (49)         (25)         (15)         (23)         (26)         (23)         
      Edema                                                         1 (4%)                                                          
      Ulcer                                            3 (6%)       1 (4%)                                 1 (4%)                   
      Arteriole, Submucosa, Thrombosis                 1 (2%)                                                                       
      Mucosa, Mineralization, Multifocal                                                                   1 (4%)                   
   Tongue                                                                                    (1)          (2)                       
      Cyst                                                                                                 1 (50%)                  
   Tooth                                                           (1)                                                              
      Peridontal Tissue, Inflammation, Chronic                                                                                      
          Active                                                    1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (28)         (18)         (25)         (29)         (29)         
      Dilatation                                                                 1 (6%)                                             
      Infarct                                                                                              1 (3%)                   
      Atrium, Dilatation                                                         2 (11%)                   1 (3%)                   
      Atrium Left, Thrombosis                          1 (2%)       1 (4%)       1 (6%)       3 (12%)      2 (7%)       2 (7%)      
      Endocardium, Proliferation                                                                           1 (3%)                   
      Mitral Valve, Thrombosis                                                                1 (4%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   15                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1           0-3           3-3        10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
CARDIOVASCULAR SYSTEM - CONT                                                                                                        
      Myocardium, Degeneration, Multifocal            39 (78%)     22 (79%)     14 (78%)     16 (64%)     25 (86%)     27 (93%)     
      Myocardium, Fibrosis, Focal                      1 (2%)                                                                       
      Myocardium, Inflammation, Chronic, Focal         1 (2%)                    2 (11%)                                            
      Myocardium, Inflammation, Chronic, Multifocal    1 (2%)                    2 (11%)                                            
      Myocardium, Inflammation, Chronic Active,                                                                                     
           Multifocal                                                                         1 (4%)                                
      Myocardium, Inflammation, Multifocal,                                                                                         
          Necrotizing                                  1 (2%)                                                                       
      Myocardium, Mineralization, Focal                             1 (4%)                                                          
      Valve, Bacterium                                 2 (4%)                                              1 (3%)                   
      Valve, Inflammation, Chronic Active              2 (4%)                                                                       
      Valve, Thrombosis                                1 (2%)                                              1 (3%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (50)         (50)         (48)         (49)         (47)         (49)         
      Hyperplasia, Nodular                            20 (40%)     10 (20%)     13 (27%)      8 (16%)     10 (21%)     19 (39%)     
      Hypertrophy, Focal                               1 (2%)       1 (2%)       2 (4%)                    3 (6%)       3 (6%)      
      Inflammation, Necrotizing                                                               1 (2%)                                
      Mineralization, Multifocal                                                 1 (2%)                                             
      Necrosis, Coagulative, Diffuse                                                                       1 (2%)                   
      Vacuolization Cytoplasmic, Focal                 1 (2%)                    1 (2%)                                             
   Adrenal Gland, Medulla                             (50)         (50)         (50)         (49)         (48)         (49)         
      Hyperplasia                                                   1 (2%)                    1 (2%)                                
      Hyperplasia, Nodular                            14 (28%)     25 (50%)     26 (52%)     24 (49%)     30 (63%)     21 (43%)     
      Inflammation, Necrotizing                                                               1 (2%)                                
      Necrosis, Coagulative, Diffuse                                                                       1 (2%)                   
   Parathyroid Gland                                  (47)         (26)         (17)         (24)         (26)         (29)         
      Hyperplasia, Diffuse                             2 (4%)                                                                       
   Pituitary Gland                                    (50)         (34)         (20)         (31)         (30)         (27)         
      Pars Distalis, Angiectasis, Focal                1 (2%)       1 (3%)                                 1 (3%)                   
      Pars Distalis, Cyst                              1 (2%)                                 2 (6%)       1 (3%)                   
      Pars Distalis, Hyperplasia                       1 (2%)                                                                       
      Pars Distalis, Hyperplasia, Nodular              6 (12%)      2 (6%)       1 (5%)       4 (13%)      3 (10%)      2 (7%)      
      Pars Nervosa, Inflammation, Multifocal,                                                                                       
          Subacute                                     1 (2%)                                                                       
   Thyroid Gland                                      (49)         (26)         (14)         (22)         (27)         (23)         
      Necrosis, Caseous, Focal                         1 (2%)                                                                       
      C-Cell, Hyperplasia                             37 (76%)     13 (50%)      7 (50%)     17 (77%)     19 (70%)     16 (70%)     
      Follicle, Dilatation, Focal                                   1 (4%)                                                          
      Follicle, Dilatation, Multifocal                                                        1 (5%)       1 (4%)                   
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   16                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1           0-3           3-3        10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (48)         (27)         (17)         (24)         (27)         (30)         
      Granuloma Sperm                                  1 (2%)                                              1 (4%)                   
      Inflammation, Chronic                                                      1 (6%)                                             
   Preputial Gland                                    (49)         (27)         (18)         (24)         (33)         (29)         
      Autolysis, Diffuse                                                                                   1 (3%)                   
      Hyperplasia                                      1 (2%)       1 (4%)       1 (6%)                                 1 (3%)      
      Inflammation, Chronic                           28 (57%)     18 (67%)     15 (83%)     21 (88%)     25 (76%)     21 (72%)     
      Inflammation, Chronic Active                     4 (8%)       5 (19%)      2 (11%)      2 (8%)       4 (12%)      7 (24%)     
      Duct, Ectasia                                                                           1 (4%)       2 (6%)       1 (3%)      
   Prostate                                           (49)         (27)         (17)         (24)         (28)         (29)         
      Granuloma                                        1 (2%)                                                           1 (3%)      
      Hemorrhage                                       1 (2%)                                                                       
   Seminal Vesicle                                    (3)          (1)          (1)                                                 
      Hemorrhage                                       1 (33%)                                                                      
   Testes                                             (50)         (50)         (50)         (48)         (50)         (49)         
      Autolysis, Diffuse                                                                                   1 (2%)                   
      Granuloma Sperm                                  1 (2%)                                                                       
      Necrosis                                         2 (4%)                                                                       
      Artery, Inflammation, Chronic                    1 (2%)                                                                       
      Interstitial Cell, Hyperplasia                   1 (2%)       1 (2%)       2 (4%)                                 1 (2%)      
      Seminiferous Tubule, Atrophy                     4 (8%)       9 (18%)     15 (30%)     12 (25%)     13 (26%)      9 (18%)     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (26)         (16)         (23)         (28)         (29)         
      Femoral, Hyperplasia                            21 (42%)     20 (77%)     11 (69%)     15 (65%)     16 (57%)     16 (55%)     
      Femoral, Myelofibrosis                           1 (2%)                                              1 (4%)                   
   Lymph Node                                         (50)         (27)         (19)         (26)         (29)         (29)         
      Lumbar, Sinus, Ectasia                                        1 (4%)                                                          
      Mandibular, Hyperplasia, Lymphoid                                          1 (5%)                                             
      Mandibular, Hyperplasia, Plasma Cell                                                                              1 (3%)      
      Mandibular, Inflammation, Necrotizing                                                   1 (4%)                                
      Mediastinal, Hematopoietic Cell Proliferation    1 (2%)                                                                       
      Mediastinal, Hyperplasia, Lymphoid                                         1 (5%)                                 1 (3%)      
      Mediastinal, Infiltration Cellular,                                                                                           
          Histiocyte                                                                                                    1 (3%)      
      Mediastinal, Medulla, Fibrosis                   1 (2%)                                                                       
      Mediastinal, Sinus, Ectasia                      1 (2%)                    1 (5%)       1 (4%)                    1 (3%)      
      Sinus, Mandibular, Ectasia                       1 (2%)                    1 (5%)                                 1 (3%)      
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   17                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1           0-3           3-3        10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
   Lymph Node, Mesenteric                             (5)          (7)          (4)          (5)          (8)          (4)          
      Infiltration Cellular, Histiocyte                             1 (14%)                                                         
      Sinus, Ectasia                                   2 (40%)                   2 (50%)      2 (40%)      1 (13%)      1 (25%)     
   Spleen                                             (49)         (33)         (29)         (31)         (35)         (29)         
      Fibrosis, Diffuse                                                                       1 (3%)                                
      Fibrosis, Focal                                  2 (4%)       2 (6%)       3 (10%)      1 (3%)       3 (9%)                   
      Hematopoietic Cell Proliferation                 3 (6%)       1 (3%)       2 (7%)                    1 (3%)       1 (3%)      
      Necrosis, Focal                                                                                                   1 (3%)      
      Capsule, Fibrosis, Focal                                      1 (3%)                                                          
      Capsule, Pigmentation, Focal, Hemosiderin        1 (2%)                                                                       
      Red Pulp, Pigmentation, Diffuse, Hemosiderin                  1 (3%)                                                          
   Thymus                                             (40)         (23)         (15)         (23)         (28)         (25)         
      Ectopic Parathyroid Gland                        1 (3%)                                                                       
      Mediastinum, Inflammation, Chronic,                                                                                           
          Multifocal                                                1 (4%)                                                          
      Vein, Congestion                                              1 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (23)         (12)         (8)          (7)          (14)         (7)          
      Granuloma                                        1 (4%)                                                                       
      Hyperplasia, Cystic                             20 (87%)     11 (92%)      5 (63%)      5 (71%)     12 (86%)      6 (86%)     
   Skin                                               (49)         (29)         (20)         (31)         (29)         (30)         
      Acanthosis                                                                              1 (3%)                                
      Cyst Epithelial Inclusion                                                  1 (5%)                                             
      Fungus                                                                                  1 (3%)                                
      Hyperkeratosis                                   1 (2%)       1 (3%)                    1 (3%)                                
      Inflammation, Chronic                            2 (4%)                    1 (5%)       1 (3%)                                
      Inflammation, Granulomatous                                                1 (5%)       1 (3%)                                
      Inflammation, Necrotizing                                     1 (3%)                                                          
      Thrombosis                                                                 1 (5%)                                             
      Subcutaneous Tissue, Edema                                                                           1 (3%)                   
      Tail, Necrosis, Coagulative, Diffuse                                                                 1 (3%)                   
      Tail, Dermis, Epidermis, Bacterium                                                                   1 (3%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (49)         (27)         (18)         (25)         (29)         (27)         
      Cranium, Inflammation, Chronic, Focal                         1 (4%)                                                          
      Femur, Fibrous Osteodystrophy                    1 (2%)                                                                       
      Femur, Osteopetrosis                                                                                 1 (3%)                   
      Tibia, Fracture Healed                                                     1 (6%)                                             
   Skeletal Muscle                                    (1)                       (1)                       (1)                       
      Hindlimb, Inflammation, Subacute                 1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   18                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1           0-3           3-3        10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (27)         (17)         (24)         (29)         (29)         
      Abscess                                                                                              1 (3%)                   
      Hemorrhage                                                    1 (4%)                                                          
      Infarct                                          2 (4%)       4 (15%)      2 (12%)                                            
      Mineralization, Focal                            1 (2%)                                                                       
      Artery, Bacterium                                                                                    1 (3%)                   
      Cerebellum, Neuron, Necrosis, Focal                                                                  1 (3%)                   
      Hypothalamus, Compression                        8 (16%)      4 (15%)      1 (6%)       3 (13%)      5 (17%)      2 (7%)      
      Ventricle, Hydrocephalus                                                                             1 (3%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (27)         (18)         (24)         (30)         (29)         
      Bacterium                                                                  1 (6%)                                             
      Congestion                                                    2 (7%)       2 (11%)                                2 (7%)      
      Alveolar Epithelium, Hyperplasia                                                        1 (4%)                                
      Alveolus, Hemorrhage                                          1 (4%)       4 (22%)      3 (13%)      1 (3%)                   
      Alveolus, Hemorrhage, Multifocal                                                                     1 (3%)                   
      Artery, Mineralization                           2 (4%)                                 2 (8%)                                
      Interstitium, Hemorrhage, Chronic, Multifocal                                                                     1 (3%)      
      Interstitium, Inflammation, Chronic                                                                               1 (3%)      
      Interstitium, Inflammation, Chronic, Focal       2 (4%)       1 (4%)       2 (11%)                   1 (3%)                   
      Interstitium, Inflammation, Chronic,                                                                                          
          Multifocal                                   2 (4%)       3 (11%)      1 (6%)       2 (8%)       1 (3%)       2 (7%)      
   Nose                                               (50)         (27)         (17)         (24)         (29)         (29)         
      Sinus, Inflammation, Suppurative                                                                                  1 (3%)      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Ear                                                (1)          (1)                                    (2)          (3)          
      External Ear, Inflammation, Chronic Active       1 (100%)                                                                     
      Middle Ear, Inflammation, Chronic                                                                    1 (50%)                  
      Pinna, Acanthosis                                                                                                 1 (33%)     
      Pinna, Inflammation, Necrotizing                              1 (100%)                               1 (50%)                  
   Eye                                                (9)          (3)          (6)          (4)          (3)          (6)          
      Anterior, Synechia                                                         1 (17%)                                            
      Anterior Chamber, Hemorrhage                     1 (11%)                                                                      
      Lens Capsule, Cataract                                                                               1 (33%)                  
      Lens Crystalline, Cataract                       9 (100%)     2 (67%)      6 (100%)     4 (100%)     2 (67%)      5 (83%)     
      Posterior Chamber, Inflammation, Chronic         1 (11%)      2 (67%)                   2 (50%)      2 (67%)      2 (33%)     
      Retina, Atrophy                                  7 (78%)      1 (33%)      6 (100%)     2 (50%)                   3 (50%)     
      Sclera, Mineralization, Multifocal                                         1 (17%)                   2 (67%)                  
   Harderian Gland                                    (2)          (1)          (1)                       (1)          (1)          
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   19                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     0 PPM        0 PPM        240 PPM      800 PPM      800 PPM      800 PPM         
                                                   0-0          10-0          1-1           0-3           3-3        10-3           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Inflammation, Chronic, Multifocal                                                                    1 (100%)                 
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (28)         (21)         (28)         (31)         (30)         
      Hemorrhage, Focal                                                                                    1 (3%)                   
      Infarct                                                       1 (4%)                                                          
      Inflammation, Multifocal, Necrotizing                                                                1 (3%)                   
      Nephropathy, Multifocal                         50 (100%)    26 (93%)     20 (95%)     26 (93%)     28 (90%)     27 (90%)     
      Pelvis, Inflammation, Suppurative                                                                    1 (3%)                   
      Renal Tubule, Bacterium                                                                              1 (3%)                   
      Renal Tubule, Cyst                                                                                                1 (3%)      
      Renal Tubule, Cytoplasmic Alteration             1 (2%)                                                                       
   Urinary Bladder                                    (48)         (26)         (15)         (23)         (27)         (24)         
      Dilatation                                                    1 (4%)                                                          
      Inflammation, Acute                                                                                  1 (4%)                   
      Lamina Propria, Edema                                                                                1 (4%)                   
      Mucosa, Inflammation, Proliferative                                                     1 (4%)                                
      Transitional Epithelium, Metaplasia, Focal,                                                                                   
           Squamous                                                                                                     1 (4%)      
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   20                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     2400 PPM     2400 PPM                                                            
                                                    0-10        10-10                                                               
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50                                                               
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                25           17                                                               
    Natural Death                                      3            2                                                               
  Survivors                                                                                                                         
    Moribund Sacrifice                                 1            1                                                               
    Terminal Sacrifice                                21           30                                                               
  Animals Examined Microscopically                    50           50                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (47)         (48)                                                             
      Ulcer                                                         1 (2%)                                                          
      Submucosa, Edema                                 1 (2%)       1 (2%)                                                          
   Intestine Large, Colon                             (46)         (48)                                                             
      Inflammation, Chronic Active, Focal              1 (2%)                                                                       
      Parasite Metazoan                                6 (13%)      8 (17%)                                                         
      Ulcer                                            1 (2%)                                                                       
   Intestine Large, Rectum                            (47)         (49)                                                             
      Parasite Metazoan                                2 (4%)       3 (6%)                                                          
   Intestine Small, Ileum                             (47)         (48)                                                             
      Inflammation, Chronic, Diffuse                                1 (2%)                                                          
      Inflammation, Chronic, Focal                     2 (4%)                                                                       
      Ulcer                                            1 (2%)                                                                       
   Intestine Small, Jejunum                           (48)         (48)                                                             
      Inflammation, Chronic, Focal                                  2 (4%)                                                          
      Peyer's Patch, Hyperplasia                                    2 (4%)                                                          
   Liver                                              (50)         (49)                                                             
      Basophilic Focus                                 4 (8%)       7 (14%)                                                         
      Clear Cell Focus                                 1 (2%)       7 (14%)                                                         
      Degeneration, Cystic                             4 (8%)       7 (14%)                                                         
      Eosinophilic Focus                               8 (16%)      7 (14%)                                                         
      Fatty Change                                     2 (4%)       3 (6%)                                                          
      Hepatodiaphragmatic Nodule                       1 (2%)                                                                       
      Mixed Cell Focus                                 3 (6%)       6 (12%)                                                         
      Necrosis, Coagulative, Focal                     2 (4%)       1 (2%)                                                          
      Necrosis, Coagulative, Multifocal                2 (4%)       2 (4%)                                                          
      Regeneration, Focal                                           1 (2%)                                                          
      Regeneration, Multifocal                         2 (4%)                                                                       
      Centrilobular, Congestion                                     1 (2%)                                                          
      Centrilobular, Cytomegaly                       27 (54%)     31 (63%)                                                         
      Serosa, Inflammation, Chronic, Multifocal        1 (2%)                                                                       
   Mesentery                                          (6)          (4)                                                              
      Inflammation, Chronic                                         1 (25%)                                                         
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   21                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     2400 PPM     2400 PPM                                                            
                                                    0-10        10-10                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Inflammation, Chronic Active                     1 (17%)                                                                      
      Necrosis                                         1 (17%)      1 (25%)                                                         
      Fat, Necrosis                                    1 (17%)      1 (25%)                                                         
   Pancreas                                           (48)         (50)                                                             
      Acinus, Atrophy                                 18 (38%)     24 (48%)                                                         
      Artery, Inflammation, Chronic                    2 (4%)       2 (4%)                                                          
   Salivary Glands                                    (49)         (50)                                                             
      Acinus, Sublingual Gland, Atrophy                             1 (2%)                                                          
      Arteriole, Thrombosis                            1 (2%)                                                                       
      Parotid Gland, Hyperplasia, Lobular              1 (2%)                                                                       
      Parotid Gland, Inflammation, Chronic             1 (2%)                                                                       
      Submandibular Gland, Necrosis, Caseous                        1 (2%)                                                          
   Stomach, Forestomach                               (49)         (48)                                                             
      Hyperkeratosis                                   1 (2%)       3 (6%)                                                          
      Ulcer                                            2 (4%)       1 (2%)                                                          
      Submucosa, Edema                                 1 (2%)       1 (2%)                                                          
   Stomach, Glandular                                 (49)         (48)                                                             
      Inflammation, Acute                                           1 (2%)                                                          
      Inflammation, Chronic                            1 (2%)                                                                       
      Ulcer                                            2 (4%)                                                                       
      Submucosa, Edema                                 1 (2%)                                                                       
   Tooth                                              (1)                                                                           
      Gingiva, Inflammation, Necrotizing               1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)                                                             
      Arteriole, Coronary Artery, Intima, Necrosis,                                                                                 
           Fibrinoid                                                1 (2%)                                                          
      Atrium, Dilatation                               2 (4%)       1 (2%)                                                          
      Atrium Left, Thrombosis                          1 (2%)       1 (2%)                                                          
      Coronary Artery, Inflammation, Chronic                        1 (2%)                                                          
      Endocardium, Proliferation                                    1 (2%)                                                          
      Myocardium, Degeneration, Multifocal            34 (68%)     40 (80%)                                                         
      Myocardium, Fibrosis, Focal                                   1 (2%)                                                          
      Myocardium, Infarct                                           1 (2%)                                                          
      Myocardium, Inflammation, Chronic, Multifocal                 1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (49)         (50)                                                             
      Hyperplasia, Nodular                            10 (20%)     11 (22%)                                                         
   Adrenal Gland, Medulla                             (48)         (50)                                                             
      Hyperplasia                                                   1 (2%)                                                          
      Hyperplasia, Nodular                            17 (35%)     15 (30%)                                                         
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   22                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     2400 PPM     2400 PPM                                                            
                                                    0-10        10-10                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
   Parathyroid Gland                                  (49)         (44)                                                             
      Hyperplasia, Diffuse                             2 (4%)       2 (5%)                                                          
   Pituitary Gland                                    (48)         (49)                                                             
      Pars Distalis, Hyperplasia, Nodular              4 (8%)       4 (8%)                                                          
      Pars Nervosa, Inflammation, Chronic              4 (8%)       1 (2%)                                                          
   Thyroid Gland                                      (48)         (49)                                                             
      C-Cell, Hyperplasia                             36 (75%)     30 (61%)                                                         
      C-Cell, Mineralization, Multifocal                            1 (2%)                                                          
      Follicle, Dilatation, Multifocal                 1 (2%)       1 (2%)                                                          
      Follicular Cell, Hyperplasia, Nodular            1 (2%)                                                                       
      Follicular Cell, Vacuolization Cytoplasmic,                                                                                   
           Focal                                                    1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (49)         (48)                                                             
      Granuloma Sperm                                  1 (2%)                                                                       
      Inflammation, Chronic                                         1 (2%)                                                          
   Preputial Gland                                    (49)         (50)                                                             
      Hyperplasia                                      3 (6%)       2 (4%)                                                          
      Inflammation, Chronic                           44 (90%)     29 (58%)                                                         
      Inflammation, Chronic Active                     1 (2%)       5 (10%)                                                         
      Duct, Ectasia                                    3 (6%)       2 (4%)                                                          
   Testes                                             (49)         (49)                                                             
      Artery, Inflammation, Chronic                                 1 (2%)                                                          
      Interstitial Cell, Hyperplasia                   4 (8%)       5 (10%)                                                         
      Seminiferous Tubule, Atrophy                     1 (2%)       3 (6%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (49)         (50)                                                             
      Femoral, Hyperplasia                            22 (45%)     26 (52%)                                                         
   Lymph Node                                         (50)         (50)                                                             
      Inguinal, Sinus, Ectasia                                      1 (2%)                                                          
      Lumbar, Necrosis, Caseous                                     1 (2%)                                                          
      Mandibular, Hyperplasia, Plasma Cell             1 (2%)                                                                       
      Mandibular, Necrosis, Caseous                                 1 (2%)                                                          
      Mediastinal, Sinus, Ectasia                      1 (2%)                                                                       
      Renal, Sinus, Ectasia                            3 (6%)                                                                       
   Lymph Node, Mesenteric                             (8)          (8)                                                              
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   23                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     2400 PPM     2400 PPM                                                            
                                                    0-10        10-10                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Fibrosis                                         1 (13%)                                                                      
      Giant Cell                                       1 (13%)                                                                      
      Metaplasia, Focal, Osseous                       1 (13%)                                                                      
      Thrombosis                                       1 (13%)                                                                      
      Sinus, Ectasia                                   2 (25%)      3 (38%)                                                         
   Spleen                                             (50)         (50)                                                             
      Fibrosis, Focal                                  3 (6%)       2 (4%)                                                          
      Hematopoietic Cell Proliferation                              1 (2%)                                                          
   Thymus                                             (35)         (39)                                                             
      Cyst                                                          1 (3%)                                                          
      Ectopic Parathyroid Gland                                     1 (3%)                                                          
      Arteriole, Inflammation, Chronic                 1 (3%)       1 (3%)                                                          
      Arteriole, Thrombosis                            1 (3%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (19)         (18)                                                             
      Hyperplasia, Cystic                             17 (89%)     16 (89%)                                                         
   Skin                                               (49)         (50)                                                             
      Acanthosis                                       1 (2%)                                                                       
      Inflammation, Chronic                            1 (2%)                                                                       
      Inflammation, Necrotizing                        2 (4%)                                                                       
      Sebaceous Gland, Hyperplasia                     1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)                                                             
      Femur, Fibrous Osteodystrophy                                 1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)                                                             
      Infarct                                          2 (4%)       2 (4%)                                                          
      Mineralization, Focal                                         1 (2%)                                                          
      Fourth Ventricle, Hydrocephalus                               1 (2%)                                                          
      Hypothalamus, Compression                        3 (6%)       2 (4%)                                                          
      Third Ventricle, Hydrocephalus                   1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   24                                                              
NTP Experiment-Test: 05075-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         DIPHENYLHYDANTOIN                                     Date: 09/09/94  
Route: DOSED FEED                                                                                                 Time: 09:05:49  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     2400 PPM     2400 PPM                                                            
                                                    0-10        10-10                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)                                                             
      Inflammation, Focal, Subacute                                 1 (2%)                                                          
      Artery, Mineralization                                        3 (6%)                                                          
      Interstitium, Inflammation, Chronic, Diffuse     1 (2%)       1 (2%)                                                          
      Interstitium, Inflammation, Chronic, Focal       2 (4%)                                                                       
      Interstitium, Inflammation, Chronic,                                                                                          
          Multifocal                                   1 (2%)       1 (2%)                                                          
   Trachea                                            (50)         (50)                                                             
      Lamina Propria, Inflammation, Chronic            1 (2%)       2 (4%)                                                          
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 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Ear                                                             (3)                                                              
      Middle Ear, Inflammation, Chronic                             1 (33%)                                                         
   Eye                                                (6)          (8)                                                              
      Lens Crystalline, Cataract                       4 (67%)      7 (88%)                                                         
      Posterior Chamber, Inflammation, Chronic         1 (17%)      3 (38%)                                                         
      Retina, Atrophy                                  2 (33%)      5 (63%)                                                         
      Retina, Mineralization, Focal                                 1 (13%)                                                         
   Harderian Gland                                    (4)                                                                           
      Inflammation, Chronic, Multifocal                2 (50%)                                                                      
   Zymbal's Gland                                     (1)                                                                           
      Inflammation, Suppurative                        1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)                                                             
      Cyst                                                          2 (4%)                                                          
      Hemorrhage                                                    1 (2%)                                                          
      Nephropathy, Multifocal                         48 (96%)     49 (98%)                                                         
      Fat, Hematopoietic Cell Proliferation                         1 (2%)                                                          
   Urinary Bladder                                    (49)         (49)                                                             
      Dilatation                                       2 (4%)                                                                       
      Inflammation, Chronic                            1 (2%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
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NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.