[Epithelioid hemangioendothelioma mimicking an occipital artery aneurysm].

INTRODUCTION: Epithelioid hemangioendothelioma (EHE) is a unique tumor of soft tissues, primarily occurring in adults. It is characterized by the proliferation of epithelioid or histiocytoid endothelial cells. Its clinical course being close to that of hemangioma and conventional angiosarcoma, the term epithelioid hemangioendothelioma was suggested. CASE REPORT: The authors report the case of 29-year-old women complaining of a right occipital nodule of the scalp, diagnosed later as an epithelioid hemangioendothelioma located in the scalp and appearing like an aneurysm of the occipital artery on clinical examination and on radiological investigations. On first clinical examination this tumor mimicked a sebaceous cyst. However during history taking we noted headaches and palpation revealed a pulsatile mass with a thrill. An aneurysm of the occipital artery was suspected according to ultra-sound and MRI findings. The treatment was a wide and complete excision of the lesion. Finally it was the histological examination which confirmed the diagnosis of epithelioid hemangioendothelioma. There was no evidence of local recurrence at the twelve-month follow-up. DISCUSSION: This case is unusual on the following points: a rare occurrence of this kind of tumors, especially in the scalp region, arterial origin of the tumor, but also the fact that it mimicked an aneurysm of the occipital artery. Epithelioid hemangioendotheliomas belong to the epithelioid vascular tumor spectrum. They have in common the morphologic epithelioid aspect of endothelial tumor cells. Cutaneous involvement is rare and often associated with multi-systemic localizations.