title: Neoplasms and related proliferative lesions in control Sprague-Dawley rats from carcinogenicity studies. Historical data and diagnostic considerations.
abstract: Historical data are presented for neoplasms and related proliferative lesions from 1,170 Sprague-Dawley rats that served as controls in 9 carcinogenicity (2 year) studies conducted in the Safety Evaluation Facility of Ciba-Geigy Corporation, Summit, New Jersey. The most common neoplasm was pituitary adenoma, which occurred in 62.2% of the male and 84.7% of the female rats. Incidences of other neoplasms that occurred in more than 6.0% of the rats were, for males, benign pheochromocytoma (19.0%), cutaneous keratoacanthoma (7.9%), pancreatic islet cell adenoma (7.5%), benign testicular interstitial cell tumor (6.5%), and thyroid C-cell adenoma (6.5%). For females these incidences were mammary fibroadenoma (31.3%), mammary adenocarcinoma (16.8%), and mammary adenoma (6.5%). Focal cortical hypertrophy/cystic degeneration of the adrenal, a focal nonneoplastic lesion of zona fasciculata cells that often degenerate into large cysts, was present in 23.4% of all male and 82.7% of all female rats. Criteria for the differential diagnoses of selected neoplasms and related lesions are presented.
authors: Research Department, Ciba-Geigy Corporation, Summit, New Jersey 07901.
authors: D N
authors: DN
authors: McMartin
authors: P S
authors: PS
authors: Sahota
authors: D E
authors: DE
authors: Gunson
authors: H H
authors: HH
authors: Hsu
authors: R H
authors: RH
authors: Spaet
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D005260:Female; D008297:Male; D009374:Neoplasms, Experimental / Q000453:epidemiology / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley / Q000033:anatomy & histology*; D012016:Reference Values
chemical_list: D002273:Carcinogens