Pitfalls in the diagnosis of hepatic epithelioid hemangioendothelioma by FNA and needle core biopsy

Abstract

Epithelioid hemangioendothelioma (EHE) of the liver is an extremely rare tumor that masquerades as an epithelial neoplasm and poses significant diagnostic pitfalls for the cytopathologist. This report describes a 64-year-old woman whom on computerized tomography was found to have multiple peripherally calcified hypodense lesions throughout the liver and an ipsilateral adrenal mass. Fine needle aspiration and needle cores biopsies of the largest liver lesion showed epithelioid cells and spindle cells in fibrous stroma. The epithelioid cells had round or oval, hyperchromatic nuclei with smooth nuclear contours, delicate cytoplasm and indistinct cytoplasmic borders. Rare cells had intracellular vascular lumen containing fragmented or intact red blood cells. The cells were individually dispersed or arranged in nests and vague tubular arrays. No mitotic figures or necrosis were seen. An immunohistochemical profile demonstrated diffuse CD31 and focal CD 34 and nuclear Fli-1 immunoexpression and low Ki-67 proliferative activity (1%) within lesional cells confirming the diagnosis of EHE. The differential diagnosis of EHE which includes cholangiocarcinoma, hepatocellular carcinoma, metastatic carcinoma and melanoma is discussed.