Unusual hemangioendothelioma of the liver with epithelioid morphology associated with marked eosinophilia: Autopsy case

Vascular neoplasms characterized by epithelioid endothelial cells consist of several different entities from benignity to high-grade malignancy. Because of histological overlap between them, there is substantial difficulty in classifying them correctly. The present patient, a 33-year-old man, presented with hepatomegaly, striking eosinophilia and elevated serum interleukin-5 level. Biopsy and autopsy revealed an unusual epithelioid vascular tumor in the liver, which is histologically distinct from epithelioid hemangioma, epithelioid hemangioendothelioma, or epithelioid angiosarcoma. The tumor cells had vasoformative and partly solid growth with no severe nuclear atypia and very low mitotic activity, and the histological features were similar to those of the entity recognized as hemangioendothelioma of bone. Organs other than the liver, for example the testes and bone, were also involved. This tumor should be considered in the differential diagnosis of severe eosinophilia.