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https://ntp.niehs.nih.gov/go/9828

Toxic equivalency factor evaluation (TCDD): Target Organs and Levels of Evidence for TR-521

Toxicology and Carcinogenesis Studies of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) (CASRN 1746-01-6) in Female Harlan Sprague-Dawley Rats (Gavage Studies)

Chemical (Study Title)
CASRN		Peer Review DateRoute/Exposure LevelsStudy Laboratory
TEF evaluation (TCDD)
1746-01-6		02/17/2004Gavage
FEMALE RATS ONLY: TCDD -- 0, 3, 10, 22, 46, OR 100 NG/KG; 100/DOSE		Battelle Columbus Laboratory

Levels of Evidence

Female Rats: Clear Evidence
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Liver: ADENOMA 0/53 0/54 0/53 0/53 1/53 13/53 2/50 OR CHOLANGIOCARCINOMA 0/53 0/54 0/53 1/53 4/53 25/53 2/50
  • Lung: CYSTIC KERATINIZING EPITHELIOMA 0/53 0/54 0/53 0/52 0/53 9/52 0/50
  • Oral Cavity: GINGIVAL SQAMOUS CELL CARCINOMA (ORAL MUCOSA) 1/53 2/54 1/53 0/53 4/53 10/53 5/50
  • Uterus/Cervix: SQUAMOUS CELL CARCINOMA 0/53 0/54 0/53 0/53 5/53 0/53 2/50
May Have Been Related
  • Pancreas Acinar Cell: ADENOMA OR CARCINOMA 0/51 0/54 0/52 0/53 0/52 3/51 1/49
  • Liver: HEPATOCHOLANGIOMA 0/53 0/54 0/53 0/53 0/53 2/53 0/50 OR CHOLANGIOMA 0/53 0/54 0/53 0/53 0/53 0/53 1/50
Non-Neoplastic Lesions
  • LIVER: HEPATOCYTE HYPERTROPHY; MULTINUCLEATED HEPATOCYTE; EOSINOPHILIC FOCUS; INFLAMMATION; PIGMENTATION; DIFFUSE FATTY CHANGE; NECROSIS; OVAL CELL HYPERPLASIA; BILE DUCT HYPERPLASIA; BILE DUCT CYST; NODULAR HYPERPLASIA; PORTAL FIBROSIS; TOXIC HEPATOPATHY; CHOLANGIOFIBROSIS
  • LUNG: ALVEOLAR EPITHELIUM, METAPLASIA, BRONCHIOLAR
  • ORAL MUCOSA: GINGIVAL SQUAMOUS HYPERPLASIA
  • PANCREAS: ACINAR CYTOPLASMIC VACUOLIZATION; CHRONIC ACTIVE INFLAMMATION; ACINAR ATROPHY; ARTERIAL CHRONIC ACTIVE INFLAMMATION
  • THYMUS: ATROPHY; SEVERITY OF ATROPHY
  • ADRENAL CORTEX: ATROPHY; HYPERPLASIA
  • HEART: CARDIOMYOPATHY
  • CLITORAL GLAND: CYSTIC DUCT
  • KIDNEY: NEPHROPATHY; SEVERITY OF NEPHROPATHY
  • FORESTOMACH: SQUAMOUS HYPERPLASIA
  • MESENTERY: CHRONIC ACTIVE ARTERY INFLAMMATION
  • THYROID GLAND: FOLLICULAR CELL HYPERTROPHY