Epithelioid hemangioendothelioma of the liver (case report)
Epitheliolid hemangioendothelioma of the liver is a very rare vascular tumor. We report the case of this tumor found during the autopsy of a 74-year-old man. The liver was infiltrated by multiple greyish nodes (diam. 3-30 mm), partially calcified. Microscopically, the tumor was composed of dense sclerotic and fibrous stroma with focal calcifications. In this stroma, groups and cords of irregular cells of two main types were dispersed. The first type was represented by big cells with large clear eosinophilic cytoplasm. The second cell type was characterised by medium-sized elongated, sometimes bizarre-shaped cells. Tumorous cells did not produce mucin. Immunohistochemically, the tumorous cells were positive for FVIIIR--Ag, actin, vimentin, and desmin and also showed disperse weak positivity for S100 protein. Staining for epithelial membrane antigene (EMA), keratins, and CD68 was negative. Neoplastic cells were positive for Ulex europaeus lectin. Electronmicroscopically, the tumorous cells had irregular nuclei, lobular or cleft shape with one or two nucleoli. Cytoplasm contained a high amount of intermediate filaments forming large aggregates. The cells were connected by desmosomes and partially surrounded by dense basal lamina. The diagnosis of epithelioid hemangioendothelioma is based on a histological picture, supported by immunohistochemical positivity for FVIIIR: Ag and Ulex europaeus and by additional ultrastructural study.