Aggressive epithelioid hemangioendothelioma of the lower extremity: a case report and review of the literature.

A case of epithelioid hemangioendothelioma (EHE) of the left lower extremity in a 50-year-old male is discussed. The neoplasm presented as a tan-purple, painful mass involving the fourth digit of the left foot. Following an excisional biopsy and partial amputation of the fourth digit, the lesion recurred with a multifocal distribution. A physical exam following the recurrence demonstrated multiple palpable lymph nodes in the left inguinal region. A complete amputation of the fourth digit was performed in conjunction with local excisions of the remaining lesions. Additionally, an inguinal lymphadenectomy was performed for staging purposes. Histologically, the tumor was predominantly composed of epithelioid endothelial cells forming nests, cords, and sheets and occasionally forming irregular, primitive vascular structures. Less commonly, nests of tumor cells assumed a spindled morphology. Patches of necrosis and hemorrhage were apparent throughout the neoplasm. There was minimal atypia and mitoses were not identified. Immunohistochemical stains for CD34, CD31, and Ulex europaeus antigens were positive in tumor cells. This case illustrates the potential aggressive behavior of this rare neoplasm and argues against the designation "tumor of low-grade malignancy" with which it is commonly attributed.