National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/5332

TDMS Study 96007-04 Pathology Tables

NTP Experiment-Test: 96007-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                        TOXIC EQUIVALENCY FACTOR EVALUATION (DIOXIN MIXTURE)                   Date: 09/29/03
Route: GAVAGE                                                                                                     Time: 12:03:19

                                                          FINAL#4/RATS




       Facility:  Battelle Columbus Laboratory

       Chemical CAS #:  TEFDIOXINMIX

       Lock Date:  09/12/01

       Cage Range:  All

       Reasons For Removal:    25018 Dosing Accident                   25019 Moribund Sacrifice
                               25020 Natural Death                     25021 Terminal Sacrifice

       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: 96007-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                        TOXIC EQUIVALENCY FACTOR EVALUATION (DIOXIN MIXTURE)                   Date: 09/29/03    
Route: GAVAGE                                                                                                     Time: 12:03:19    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX                     
                                                   CONTROL      TEQ=10       TEQ=22       TEQ=46       TEQ=100                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          98           98           98           98           98                        
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                26           25           22           25           33                        
    Natural Death                                     11            5            6            4           10                        
    Dosing Accident                                                              1            1            2                        
  Survivors                                                                                                                         
    Terminal Sacrifice                                16           23           24           23            8                        
                                                                                                                                    
  Animals Examined Microscopically                    53           53           53           53           53                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (53)         (53)         (53)         (53)         (53)                      
      Muscularis, Inflammation                                      2 (4%)       1 (2%)       1 (2%)                                
   Intestine Large, Colon                             (53)         (52)         (53)         (53)         (51)                      
      Parasite Metazoan                                                          1 (2%)                                             
   Intestine Large, Rectum                            (52)         (53)         (53)         (53)         (52)                      
      Parasite Metazoan                                2 (4%)       4 (8%)       5 (9%)       1 (2%)                                
      Artery, Inflammation, Chronic Active                                                    2 (4%)       3 (6%)                   
      Serosa, Inflammation                                                                                 1 (2%)                   
   Intestine Large, Cecum                             (51)         (53)         (53)         (53)         (51)                      
      Artery, Inflammation, Chronic Active                                                                 1 (2%)                   
   Intestine Small, Duodenum                          (52)         (53)         (53)         (53)         (52)                      
      Serosa, Inflammation, Chronic Active                                                                 1 (2%)                   
   Liver                                              (53)         (53)         (53)         (53)         (51)                      
      Angiectasis                                      3 (6%)       2 (4%)                                 3 (6%)                   
      Basophilic Focus                                 9 (17%)     14 (26%)     10 (19%)      5 (9%)       8 (16%)                  
      Basophilic Focus, Multiple                      15 (28%)     12 (23%)      3 (6%)       7 (13%)      8 (16%)                  
      Cholangiofibrosis                                             2 (4%)       3 (6%)       4 (8%)      17 (33%)                  
      Clear Cell Focus                                              1 (2%)       1 (2%)                                             
      Clear Cell Focus, Multiple                       1 (2%)                                 1 (2%)                                
      Degeneration, Cystic                             1 (2%)                                 1 (2%)       2 (4%)                   
      Eosinophilic Focus                               4 (8%)       2 (4%)       5 (9%)       5 (9%)                                
      Eosinophilic Focus, Multiple                     1 (2%)       7 (13%)      6 (11%)     15 (28%)     19 (37%)                  
      Fatty Change, Diffuse                            3 (6%)       5 (9%)      14 (26%)     34 (64%)     36 (71%)                  
      Fatty Change, Focal                              3 (6%)       4 (8%)       7 (13%)      2 (4%)       1 (2%)                   
      Hematopoietic Cell Proliferation                16 (30%)     18 (34%)     19 (36%)      8 (15%)      9 (18%)                  
      Hepatodiaphragmatic Nodule                                                 1 (2%)                                             
      Hyperplasia, Nodular                                          1 (2%)       3 (6%)      11 (21%)     38 (75%)                  
      Inflammation                                    36 (68%)     50 (94%)     45 (85%)     50 (94%)     50 (98%)                  
      Karyomegaly                                                                             1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    2                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                        TOXIC EQUIVALENCY FACTOR EVALUATION (DIOXIN MIXTURE)                   Date: 09/29/03    
Route: GAVAGE                                                                                                     Time: 12:03:19    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX                     
                                                   CONTROL      TEQ=10       TEQ=22       TEQ=46       TEQ=100                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Mixed Cell Focus                                 4 (8%)       5 (9%)       5 (9%)       1 (2%)                                
      Mixed Cell Focus, Multiple                      17 (32%)     27 (51%)     30 (57%)     35 (66%)     17 (33%)                  
      Necrosis                                         3 (6%)       1 (2%)       9 (17%)      3 (6%)      15 (29%)                  
      Pigmentation                                     4 (8%)      35 (66%)     41 (77%)     48 (91%)     51 (100%)                 
      Toxic Hepatopathy                                             5 (9%)      14 (26%)     38 (72%)     47 (92%)                  
      Bile Duct, Cyst                                  1 (2%)       3 (6%)       3 (6%)       4 (8%)       9 (18%)                  
      Bile Duct, Dilatation                            1 (2%)                                              1 (2%)                   
      Bile Duct, Fibrosis                              3 (6%)       2 (4%)       1 (2%)       5 (9%)       1 (2%)                   
      Bile Duct, Hyperplasia                           2 (4%)       3 (6%)       5 (9%)      25 (47%)     42 (82%)                  
      Centrilobular, Degeneration                      3 (6%)       2 (4%)       1 (2%)       1 (2%)       6 (12%)                  
      Centrilobular, Fibrosis                                                                              1 (2%)                   
      Hepatocyte, Hypertrophy                          1 (2%)      27 (51%)     34 (64%)     46 (87%)     50 (98%)                  
      Hepatocyte, Multinucleated                                   12 (23%)     10 (19%)     39 (74%)     51 (100%)                 
      Oval Cell, Hyperplasia                                        1 (2%)       1 (2%)      26 (49%)     42 (82%)                  
      Portal, Fibrosis                                                                                    11 (22%)                  
      Serosa, Fibrosis                                                                                     1 (2%)                   
      Serosa, Inflammation, Chronic                    1 (2%)                                                                       
   Mesentery                                                       (1)          (2)          (6)          (8)                       
      Inflammation, Chronic Active                                                                         2 (25%)                  
      Necrosis                                                                   1 (50%)                   1 (13%)                  
      Artery, Inflammation, Chronic Active                          1 (100%)                  3 (50%)      6 (75%)                  
      Fat, Necrosis                                                              1 (50%)      2 (33%)                               
   Oral Mucosa                                        (10)         (18)         (19)         (29)         (31)                      
      Gingival, Hyperplasia, Squamous                  8 (80%)     17 (94%)     18 (95%)     26 (90%)     30 (97%)                  
   Pancreas                                           (52)         (53)         (53)         (53)         (51)                      
      Degeneration                                     1 (2%)                                                                       
      Inflammation, Chronic Active                     3 (6%)       1 (2%)       6 (11%)      7 (13%)     16 (31%)                  
      Inflammation, Granulomatous                                                             1 (2%)                                
      Acinus, Atrophy                                  3 (6%)       2 (4%)       7 (13%)      7 (13%)     20 (39%)                  
      Acinus, Hyperplasia                              2 (4%)                    1 (2%)                                             
      Acinus, Vacuolization Cytoplasmic                1 (2%)                    3 (6%)      15 (28%)     30 (59%)                  
      Artery, Inflammation, Chronic Active                          6 (11%)      3 (6%)       8 (15%)     14 (27%)                  
      Duct, Cyst                                                                 1 (2%)                                             
      Duct, Dilatation                                                                                     5 (10%)                  
      Duct, Inflammation, Chronic Active                                                                   2 (4%)                   
   Salivary Glands                                    (53)         (53)         (53)         (53)         (53)                      
      Atrophy                                          1 (2%)                                                                       
      Inflammation                                     2 (4%)                                 1 (2%)                                
      Mineralization                                                                          1 (2%)                                
   Stomach, Forestomach                               (53)         (53)         (53)         (53)         (52)                      
      Cyst                                                                                    1 (2%)       1 (2%)                   
      Diverticulum                                                                            1 (2%)                                
      Edema                                            1 (2%)                    1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    3                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                        TOXIC EQUIVALENCY FACTOR EVALUATION (DIOXIN MIXTURE)                   Date: 09/29/03    
Route: GAVAGE                                                                                                     Time: 12:03:19    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX                     
                                                   CONTROL      TEQ=10       TEQ=22       TEQ=46       TEQ=100                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Erosion                                                                    1 (2%)                                             
      Hyperkeratosis                                                             2 (4%)       2 (4%)                                
      Hyperplasia, Squamous                            5 (9%)       1 (2%)       4 (8%)       9 (17%)      6 (12%)                  
      Inflammation                                     2 (4%)                    2 (4%)       1 (2%)       3 (6%)                   
      Mineralization                                   1 (2%)                    4 (8%)       2 (4%)                                
      Ulcer                                            3 (6%)                    2 (4%)       1 (2%)       2 (4%)                   
      Artery, Inflammation, Chronic Active                                                    2 (4%)       1 (2%)                   
   Stomach, Glandular                                 (53)         (53)         (53)         (53)         (52)                      
      Erosion                                          1 (2%)                                                                       
      Mineralization                                   2 (4%)       4 (8%)       3 (6%)       3 (6%)       1 (2%)                   
      Artery, Inflammation, Chronic Active                                                                 2 (4%)                   
   Tongue                                             (1)                                                 (1)                       
      Infiltration Cellular                                                                                1 (100%)                 
   Tooth                                              (24)         (23)         (27)         (37)         (30)                      
      Peridontal Tissue, Inflammation                 23 (96%)     21 (91%)     22 (81%)     34 (92%)     30 (100%)                 
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (53)         (53)         (53)         (52)         (53)                      
      Aorta, Mineralization                                                                   1 (2%)       3 (6%)                   
   Heart                                              (53)         (53)         (53)         (52)         (53)                      
      Cardiomyopathy                                  11 (21%)     26 (49%)     31 (58%)     30 (58%)     32 (60%)                  
      Inflammation, Suppurative                        1 (2%)                                              1 (2%)                   
      Mineralization                                                                          1 (2%)                                
      Necrosis                                                                                             1 (2%)                   
      Thrombosis                                       1 (2%)                                              1 (2%)                   
      Artery, Degeneration                                                                    1 (2%)       1 (2%)                   
      Artery, Inflammation, Chronic Active                                                    1 (2%)       1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (52)         (53)         (53)         (53)         (51)                      
      Angiectasis                                     15 (29%)     20 (38%)     18 (34%)     17 (32%)      8 (16%)                  
      Atrophy                                                       3 (6%)                                18 (35%)                  
      Degeneration, Cystic                             9 (17%)     15 (28%)     19 (36%)     25 (47%)     16 (31%)                  
      Hematopoietic Cell Proliferation                                           1 (2%)                    1 (2%)                   
      Hyperplasia                                     12 (23%)     26 (49%)     23 (43%)     25 (47%)     21 (41%)                  
      Hypertrophy                                     44 (85%)     45 (85%)     47 (89%)     46 (87%)     45 (88%)                  
      Inflammation                                                                            1 (2%)                                
      Mineralization                                                1 (2%)                                 1 (2%)                   
      Necrosis                                         2 (4%)                    2 (4%)                    2 (4%)                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    4                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                        TOXIC EQUIVALENCY FACTOR EVALUATION (DIOXIN MIXTURE)                   Date: 09/29/03    
Route: GAVAGE                                                                                                     Time: 12:03:19    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX                     
                                                   CONTROL      TEQ=10       TEQ=22       TEQ=46       TEQ=100                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Thrombosis                                                    1 (2%)                                                          
      Vacuolization Cytoplasmic                        6 (12%)     13 (25%)     11 (21%)      7 (13%)     15 (29%)                  
      Capsule, Inflammation                                                                   1 (2%)       1 (2%)                   
   Adrenal Medulla                                    (52)         (53)         (53)         (53)         (51)                      
      Hyperplasia                                     10 (19%)     21 (40%)     12 (23%)     15 (28%)      9 (18%)                  
   Islets, Pancreatic                                 (52)         (53)         (53)         (53)         (51)                      
      Hyperplasia                                                                1 (2%)       2 (4%)                                
   Pituitary Gland                                    (53)         (53)         (53)         (53)         (53)                      
      Angiectasis                                      6 (11%)                   1 (2%)       2 (4%)       3 (6%)                   
      Cyst                                             1 (2%)                    1 (2%)       2 (4%)                                
      Cytoplasmic Alteration                                        3 (6%)                                                          
      Hemorrhage                                       1 (2%)                                                                       
      Vacuolization Cytoplasmic                                     1 (2%)       2 (4%)       3 (6%)       1 (2%)                   
      Pars Distalis, Hyperplasia                      18 (34%)     19 (36%)     24 (45%)     20 (38%)     19 (36%)                  
      Pars Intermedia, Cyst                                                      1 (2%)                                             
   Thyroid Gland                                      (53)         (53)         (51)         (52)         (51)                      
      C-Cell, Hyperplasia                             24 (45%)     24 (45%)     20 (39%)     18 (35%)     14 (27%)                  
      Follicular Cell, Hyperplasia                     1 (2%)                                                                       
      Follicular Cell, Hypertrophy                     4 (8%)      13 (25%)     12 (24%)     18 (35%)     23 (45%)                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (51)         (53)         (53)         (51)         (50)                      
      Hyperplasia, Squamous                                                                   1 (2%)                                
      Inflammation                                    42 (82%)     40 (75%)     37 (70%)     33 (65%)     29 (58%)                  
      Duct, Cyst                                      39 (76%)     41 (77%)     44 (83%)     39 (76%)     44 (88%)                  
   Ovary                                              (52)         (52)         (53)         (53)         (51)                      
      Atrophy                                         44 (85%)     44 (85%)     43 (81%)     49 (92%)     40 (78%)                  
      Cyst                                             8 (15%)     16 (31%)     20 (38%)     14 (26%)      7 (14%)                  
      Fibrosis                                                      1 (2%)                                                          
      Hemorrhage                                                                                           1 (2%)                   
      Inflammation, Chronic Active                                  2 (4%)       1 (2%)       2 (4%)       5 (10%)                  
      Artery, Inflammation, Chronic Active                                                                 1 (2%)                   
   Oviduct                                                         (2)                       (2)          (5)                       
      Cyst                                                          2 (100%)                               1 (20%)                  
      Inflammation, Chronic Active                                                            2 (100%)     4 (80%)                  
   Uterus                                             (52)         (53)         (53)         (53)         (51)                      
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    5                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                        TOXIC EQUIVALENCY FACTOR EVALUATION (DIOXIN MIXTURE)                   Date: 09/29/03    
Route: GAVAGE                                                                                                     Time: 12:03:19    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX                     
                                                   CONTROL      TEQ=10       TEQ=22       TEQ=46       TEQ=100                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Adenomyosis                                                   1 (2%)       1 (2%)       2 (4%)       1 (2%)                   
      Hemorrhage                                       1 (2%)                                              1 (2%)                   
      Inflammation, Chronic Active                     1 (2%)       1 (2%)       1 (2%)       1 (2%)       3 (6%)                   
      Inflammation, Suppurative                        6 (12%)      5 (9%)       9 (17%)     13 (25%)      6 (12%)                  
      Metaplasia, Squamous                            21 (40%)     32 (60%)     32 (60%)     35 (66%)     30 (59%)                  
      Necrosis                                                                                             1 (2%)                   
      Thrombosis                                                                              1 (2%)                                
      Ulcer                                                         1 (2%)                    1 (2%)                                
      Cervix, Hyperplasia, Stromal                     1 (2%)                                                                       
      Endometrium, Fibrosis                                                                                1 (2%)                   
      Endometrium, Hyperplasia, Cystic                37 (71%)     35 (66%)     34 (64%)     33 (62%)     23 (45%)                  
      Epithelium, Necrosis                             1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (53)         (53)         (53)         (53)         (53)                      
      Hyperplasia                                     36 (68%)     36 (68%)     34 (64%)     41 (77%)     48 (91%)                  
   Lymph Node                                         (4)          (1)          (2)          (9)          (11)                      
      Lumbar, Ectasia                                                            1 (50%)                                            
      Lumbar, Hemorrhage                                                         1 (50%)                                            
      Lumbar, Hyperplasia, Lymphoid                                              1 (50%)                   1 (9%)                   
      Lumbar, Hyperplasia, Plasma Cell                 1 (25%)                                3 (33%)                               
      Mediastinal, Ectasia                                          1 (100%)                  4 (44%)      2 (18%)                  
      Mediastinal, Fibrosis                                                                   1 (11%)                               
      Mediastinal, Hemorrhage                                                                 1 (11%)      2 (18%)                  
      Mediastinal, Hyperplasia, Histiocytic                                                   1 (11%)      1 (9%)                   
      Mediastinal, Hyperplasia, Lymphoid                                                                   2 (18%)                  
      Mediastinal, Hyperplasia, Plasma Cell                                                                3 (27%)                  
      Pancreatic, Ectasia                              1 (25%)                                                                      
      Pancreatic, Hyperplasia                                                                              1 (9%)                   
      Pancreatic, Hyperplasia, Histiocytic                                                                 1 (9%)                   
      Popliteal, Hyperplasia, Plasma Cell                                                     1 (11%)                               
      Renal, Hyperplasia, Histiocytic                  1 (25%)                                                                      
   Lymph Node, Mandibular                             (53)         (53)         (53)         (53)         (53)                      
      Ectasia                                                       1 (2%)       1 (2%)       2 (4%)                                
      Hemorrhage                                                                              1 (2%)                                
      Hyperplasia, Plasma Cell                        31 (58%)     42 (79%)     30 (57%)     22 (42%)     27 (51%)                  
      Necrosis, Focal                                                                         1 (2%)                                
   Lymph Node, Mesenteric                             (52)         (53)         (53)         (53)         (50)                      
      Ectasia                                          1 (2%)                                                                       
      Hemorrhage                                       1 (2%)                                              1 (2%)                   
      Hyperplasia                                                                                          1 (2%)                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    6                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                        TOXIC EQUIVALENCY FACTOR EVALUATION (DIOXIN MIXTURE)                   Date: 09/29/03    
Route: GAVAGE                                                                                                     Time: 12:03:19    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX                     
                                                   CONTROL      TEQ=10       TEQ=22       TEQ=46       TEQ=100                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Hyperplasia, Histiocytic                                                                1 (2%)       1 (2%)                   
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
      Pigmentation                                                                            1 (2%)                                
   Spleen                                             (52)         (53)         (53)         (53)         (51)                      
      Hematopoietic Cell Proliferation                43 (83%)     48 (91%)     42 (79%)     44 (83%)     42 (82%)                  
      Hemorrhage                                                                                           1 (2%)                   
      Inflammation, Suppurative                                                                            1 (2%)                   
      Necrosis                                         1 (2%)                                              1 (2%)                   
      Pigmentation                                    45 (87%)     50 (94%)     52 (98%)     47 (89%)     46 (90%)                  
      Lymphoid Follicle, Atrophy                       1 (2%)       2 (4%)       3 (6%)       2 (4%)       3 (6%)                   
      Red Pulp, Atrophy                                             1 (2%)       3 (6%)                                             
   Thymus                                             (52)         (48)         (50)         (53)         (50)                      
      Atrophy                                         32 (62%)     43 (90%)     45 (90%)     50 (94%)     48 (96%)                  
      Cyst                                             2 (4%)                                                                       
      Ectopic Thyroid                                                                         1 (2%)                                
      Hemorrhage                                                                              1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (53)         (53)         (53)         (53)         (52)                      
      Cyst                                                          3 (6%)       1 (2%)       1 (2%)                                
      Hyperplasia                                     22 (42%)      7 (13%)     14 (26%)     12 (23%)      9 (17%)                  
      Inflammation, Granulomatous                      3 (6%)       4 (8%)       1 (2%)       3 (6%)       1 (2%)                   
      Inflammation, Suppurative                                                               1 (2%)                                
   Skin                                               (53)         (53)         (53)         (53)         (53)                      
      Cyst Epithelial Inclusion                                     2 (4%)       1 (2%)       3 (6%)       3 (6%)                   
      Hyperkeratosis                                                             1 (2%)                                             
      Inflammation, Suppurative                                                               1 (2%)                                
      Ulcer                                                                                   1 (2%)       1 (2%)                   
      Hair Follicle, Atrophy                                        1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (53)         (53)         (53)         (53)         (53)                      
      Mineralization                                                             1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (53)         (53)         (53)         (53)         (53)                      
      Edema                                                                                   1 (2%)       3 (6%)                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    7                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                        TOXIC EQUIVALENCY FACTOR EVALUATION (DIOXIN MIXTURE)                   Date: 09/29/03    
Route: GAVAGE                                                                                                     Time: 12:03:19    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX                     
                                                   CONTROL      TEQ=10       TEQ=22       TEQ=46       TEQ=100                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NERVOUS SYSTEM - CONT                                                                                                               
      Gliosis                                          1 (2%)                                              1 (2%)                   
      Hemorrhage                                                    1 (2%)                                                          
      Hydrocephalus                                    1 (2%)       4 (8%)       2 (4%)       2 (4%)                                
      Inflammation, Granulomatous                                                1 (2%)                                             
      Mineralization                                   1 (2%)                    1 (2%)       1 (2%)                                
      Necrosis                                                                                             3 (6%)                   
      Artery, Degeneration                                                                                 1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (53)         (53)         (53)         (53)         (53)                      
      Congestion                                                                 1 (2%)       1 (2%)                                
      Cyst                                                                                                 1 (2%)                   
      Edema                                                                      2 (4%)       2 (4%)       1 (2%)                   
      Hemorrhage                                                                 1 (2%)                    1 (2%)                   
      Infiltration Cellular, Histiocyte               43 (81%)     50 (94%)     48 (91%)     48 (91%)     50 (94%)                  
      Inflammation                                     4 (8%)       2 (4%)       3 (6%)       1 (2%)       2 (4%)                   
      Metaplasia, Squamous                             2 (4%)                    2 (4%)       8 (15%)     11 (21%)                  
      Mineralization                                                                          1 (2%)                                
      Alveolar Epithelium, Hyperplasia                21 (40%)     25 (47%)     10 (19%)      2 (4%)       2 (4%)                   
      Alveolar Epithelium, Metaplasia, Bronchiolar                 20 (38%)     33 (62%)     41 (77%)     40 (75%)                  
      Perivascular, Inflammation, Chronic Active                                                           1 (2%)                   
   Nose                                               (53)         (53)         (53)         (53)         (53)                      
      Inflammation                                     1 (2%)       2 (4%)       2 (4%)       1 (2%)       1 (2%)                   
      Goblet Cell, Hyperplasia                                                   2 (4%)       1 (2%)                                
      Goblet Cell, Septum, Hyperplasia                                                        1 (2%)                                
      Nasolacrimal Duct, Inflammation                                                         1 (2%)                                
      Respiratory Epithelium, Hyperplasia                           1 (2%)                    4 (8%)                                
      Turbinate, Cyst                                                                         1 (2%)                                
      Turbinate, Respiratory Epithelium,                                                                                            
        Hyperplasia                                                                                        1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (53)         (53)         (53)         (53)         (53)                      
      Anterior Chamber, Ciliary Body, Iris,                                                                                         
        Inflammation, Suppurative                                                                          1 (2%)                   
      Cornea, Inflammation, Suppurative                                                                    1 (2%)                   
      Lens, Degeneration                                            1 (2%)                                                          
      Retina, Atrophy                                  1 (2%)       1 (2%)       2 (4%)       1 (2%)       3 (6%)                   
   Harderian Gland                                    (53)         (53)         (52)         (53)         (53)                      
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    8                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                        TOXIC EQUIVALENCY FACTOR EVALUATION (DIOXIN MIXTURE)                   Date: 09/29/03    
Route: GAVAGE                                                                                                     Time: 12:03:19    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX     TERT.MIX                     
                                                   CONTROL      TEQ=10       TEQ=22       TEQ=46       TEQ=100                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Inflammation                                     8 (15%)     11 (21%)      4 (8%)       5 (9%)       7 (13%)                  
      Inflammation, Chronic Active                                                                         1 (2%)                   
      Necrosis                                                                                             1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (52)         (53)         (53)         (53)         (51)                      
      Calculus Micro Observation Only                  9 (17%)      5 (9%)       8 (15%)      4 (8%)       1 (2%)                   
      Casts Protein                                                              1 (2%)       1 (2%)                                
      Cyst                                                          1 (2%)                    1 (2%)                                
      Developmental Malformation                                                                           1 (2%)                   
      Fibrosis                                                                                             1 (2%)                   
      Inflammation, Chronic                                                                   1 (2%)                                
      Inflammation, Chronic Active                     1 (2%)       1 (2%)       1 (2%)                                             
      Inflammation, Suppurative                        3 (6%)       2 (4%)       3 (6%)       3 (6%)       6 (12%)                  
      Mineralization                                  41 (79%)     48 (91%)     47 (89%)     42 (79%)     35 (69%)                  
      Nephropathy                                     26 (50%)     41 (77%)     40 (75%)     47 (89%)     49 (96%)                  
      Pelvis, Dilatation                               2 (4%)                    1 (2%)       1 (2%)       1 (2%)                   
      Pelvis, Inflammation                             2 (4%)       1 (2%)       1 (2%)       2 (4%)       1 (2%)                   
      Renal Tubule, Hyperplasia                                                               2 (4%)                                
      Renal Tubule, Necrosis                           1 (2%)                    1 (2%)                                             
      Transitional Epithelium, Hyperplasia             5 (10%)      5 (9%)       8 (15%)     10 (19%)      8 (16%)                  
   Ureter                                             (1)                       (1)          (1)          (1)                       
      Cyst                                             1 (100%)                                                                     
      Inflammation                                                               1 (100%)                                           
      Metaplasia, Squamous                                                                    1 (100%)                              
      Transitional Epithelium, Hyperplasia                                       1 (100%)     1 (100%)                              
   Urinary Bladder                                    (52)         (52)         (53)         (53)         (50)                      
      Edema                                                                                   1 (2%)                                
      Hemorrhage                                                                                           1 (2%)                   
      Inflammation                                    12 (23%)      3 (6%)       4 (8%)       8 (15%)      5 (10%)                  
      Metaplasia, Squamous                                                                    1 (2%)                                
      Transitional Epithelium, Hyperplasia                                       1 (2%)       3 (6%)       4 (8%)                   
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page    9                                                              
                                                                                                                                   
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                             ----------              END OF REPORT             ----------                                           
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NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.