Morphology of foci of altered hepatocytes and naturally-occurring hepatocellular tumors in F344 rats.
The morphology of liver tumors of F344 rats used as controls in carcinogenesis bioassays were studied. Foci of cellular alteration composed of hepatocytes with basophilic cytoplasm were found commonly in F344 rats, 2 years of age. Eosinophilic and vacuolated foci were considerably less common. The morphology of 67 nodular hepatic lesions indicated that 54 were neoplastic nodules and 13 hepatocellular carcinomas. The majority of these tumors were composed of basophilic hepatocytes. Some of the carcinomas appeared to arise within neoplastic nodules. No tumors metastasized.
D000818:Animals; D002471:Cell Transformation, Neoplastic; D005260:Female; D008113:Liver Neoplasms / Q000473:pathology*; D008114:Liver Neoplasms, Experimental / Q000473:pathology; D008297:Male; D009374:Neoplasms, Experimental / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344