Hepatic epithelioid hemangioendothelioma.

Epithelioid hemangioendothelioma (EHE) is a rare neoplasm of vascular origin with unpredictable malignant potential. We describe two patients with primary EHE of the liver and review 34 cases previously published in Japan and compare them with those in Western countries. The clinical aspects of EHE and relevant treatment results in Japanese patients were similar to those found in Western countries, the exception being the matter of difference in incidence between genders. Although this tumor type has been reported to be more frequent among women, there was no significant difference in incidence between men and women. Hepatic EHE generally behaves as a low-grade malignant tumor with a slow progression phenotype; however, this disease seems to be resistant to chemotherapy and to be lethal in some cases. Surgical resection or liver transplantation is recommended after rapid diagnosis by radiologic examination and histologic findings, including positive staining of tumor cells for factor VIII-related antigen.