Malignant Vascular Tumors of the Liver in Adults.

Hepatic angiosarcoma and epithelioid hemangioendothelioma (EHE) might be clinically considered a spectrum since, although more frequently presenting indolent behavior, EHE occasionally evolves to high-grade neoplasms. However, in most circumstances, pathological and immunohistochemical patterns define this differential diagnosis. More recently, molecular pathways for angiosarcoma and for EHE from other organs and from soft tissue have been proved different, paving the way for future morpho-molecular assessment of their hepatic counterpart. The frequency of liver involvement by Kaposi sarcoma in HIV-infected patients is lower nowadays. Histological findings and immunostaining for HHV-8 Ag are characteristic. Hepatic small vessel neoplasms have been recently recognized as important mimickers of angiosarcoma. The criteria for this differential diagnosis and the clinical behavior, up to now considered favorable, must be further studied.