[Vascular tumors of the liver. Morphology, differential diagnosis, prognosis].

A group of 5 primary angiomas of the liver (4 angiosarcomas, 1 cavernous hemangioma) was studied. Classification, differential diagnosis and pathogenesis are discussed. Angiosarcomas may be caused by exposure to thorotrast (2 of our 4 tumors) or of polyvinylchloride. Highly cellular tumors with a herringbone-pattern must be differentiated from primarily extrahepatic fibrosarcomas or myosarcomas, and highly cellular solid or medullary tumors from metastasis from a carcinoma or lymphoma. Immunohistology--also in our tumors--permits the identification of angiomas by the demonstration of factor VIII and basement membrane protein, which are negative in other tumors. The binding of lectin Ulex europaeus can also be helpful. The common benign cavernous hemangioma is diagnosed very readily morphologically, but clinical and sonographic diagnosis can be difficult. Its biological significance is to be seen merely in possible rupture and hemorrhage.