Neoplasms and nonneoplastic liver lesions in winter flounder, Pseudopleuronectes americanus, from Boston Harbor, Massachusetts.

A variety of neoplasms and nonneoplastic hepatic lesions have been noted in winter flounder, Pseudopleuronectes americanus, from Boston Harbor, Massachusetts. Inflammatory lesions include cholangiitis, pericholangiitis, pericholangial fibrosis, hepatitis, and pancreatitis. Necrotic lesions consist essentially of focal coagulative necrosis and a distinctive vacuolated cell lesion of the hepatic parenchyma. The most conspicuous and numerous proliferative lesion is macrophage aggregate hyperplasia and hypertrophy. Preneoplastic lesions include principally basophilic foci of cellular alteration and hepatocellular adenoma. Carcinomas consist of several morphologic varieties: hepatocarcinoma, cholangiocarcinoma, and anaplastic adenocarcinoma. The pathogenesis of the lesions observed is discussed with respect to anthropogenically introduced chemical contaminants and the resistant hepatocyte model of hepatocarcinogenesis. This study, and others of bottom-living food fish with enzootic neoplastic disease, warrants further evaluation, particularly with respect to possible bioaccumulation of chemical contaminants in edible tissues.