title: Spontaneous neoplasms in aged control Fischer 344 rats.
abstract: Neoplastic lesions in untreated F-344 rats (740 males and 740 females) used as controls in carcinogenicity studies were evaluated and tabulated. The incidence of spontaneous tumors was 84.3% in the males and 76.2% in the females. In males, the most common neoplasms were testicular interstitial cell tumors (79.5%) followed by mononuclear cell leukemia/lymphomas (30.5%), pituitary adenomas (20.5%), pancreatic islet cell adenomas (6.5%), thyroid c-cell adenomas (5.7%), pheochromocytomas (5.7%), skin fibromas (3.2%), keratoacanthomas (1.9%), and thyroid follicular cell adenomas (1.9%). In females, the most common neoplasms were pituitary adenomas (30.3%) followed by mononuclear cell leukemia/lymphomas (20.5%), endometrial polyps (14.1%), mammary fibroadenomas (11.1%), thyroid c-cell adenomas (5.1%), mammary adenomas (1.9%), skin fibromas (1.1%), and clitoral carcinomas (1.1%). A variety of less common neoplasms were also observed in various other organs.
authors.affiliation: Experimental Pathology Department, American Cyanamid Company, Pearl River, NY 10965.
authors.forename: M
authors.initials: M
authors.lastname: Chandra
authors.forename: C F
authors.initials: CF
authors.lastname: Frith
mesh_terms: D000818:Animals; D000830:Animals, Laboratory; D005260:Female; D008297:Male; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D051381:Rats; D011916:Rats, Inbred F344 / Q000502:physiology*