Variants of Hemangioendotheliomas of the Hepatobiliary Tract

Abstract

Apart from epithelioid hepatic hemangioendothelioma and infantile hepatic hemangioendothelioma/hepatic infantile hemangioma, there are few other endotheliomas that can manifest as primary neoplasms of the liver. Kaposiform hemangioendothelioma is a rare, locally aggressive, vascular spindle-cell tumor that resembles Kaposi's sarcoma. This neoplasm most commonly develops in the skin and the retroperitoneal space of infants and children, but is also observed in the hepatobiliary tract in rare instances. Kaposiform hemangioendothelioma is a wellknown cause of Kasabach-Merritt syndrome. Histologically, the neoplasm is characterized by nodules or lobules of rather bland-looking spindle cells which encircle slit-like, CD31and CD34-positive vascular channels. A further hemangioendotheliomatous neoplasm that develops in the liver as a primary tumor is polymorphous hemangioendothelioma.