COMBINED HEPATOCELLULAR-CARCINOMA AND CHOLANGIOCARCINOMA IN A MARE

A hepatic malignant tumour composed of both hepatocellular and cholang iocellular elements was studied histologically, immunohistochemically and electron microscopically in an 18-year-old Thoroughbred mare. Bile canaliculi and alpha-fetoprotein were useful in identifying the hepat ocellular element, and mucin and keratin were good markers of biliary differentiation. The simultaneous presence of bile canaliculi and muci n-producing cells in most of the neoplastic lesions suggested that thi s tumour arose from a stem cell with capacity to differentiate into he patocytes and biliary epithelium. (C) 1997 W.B. Saunders Company Limit ed.