抄録
We experienced a case of epithelioid hemangioendothelioma that occurred in the maxilla of a 50-year-old woman. The incidence of this disease is high in soft tissue and bones, and its development in the oral cavity has rarely been reported. The patient visited our hospital because of an asymptomatic tumor in the buccal-side gingiva. Under the diagnosis of oral benign tumor, we excised the lesion. Histopathologically the tumor had multiple alveolar structures built up of spindle cells with egg-shaped nuclei. The alveolar structures had small lumina in their central part, and hemocyte components were observed in some of them. Immunohistochemically, the tumor cells were positive for Factor VIII related antigen. Electronmicroscopy revealed micropinocytotic vesicles and multivesicular bodies. On the basis of these findings, we made a diagnosis of epithelioid hemangioendothelioma. There are clinical and histological differences between epithelioid hemangioendothelioma of the oral cavity and the other site.