Epithelioid hemangioendothelioma with osteoclast-like giant cells

Epithelioid hemangioendothelioma is an unusual entity of intermediate malignant vascular tumors and rarely admixes with multinucleated osteoclast-like giant cells. We describe such a case in a 50-year-old woman with an 1-year follow-up period. When the patient was 39 years old, a 0.7 x 1-cm firm mass was found in the left neck. She developed ascites three years later. At that time, the specimen from the neck mass was excised and found to be composed of cords of epithelioid cells in a myxoid hyaline stroma. Scattered intracytoplasmic vacuoles were seen. Immunohistochemical studies confirmed the diagnosis of epithelioid hemangioendothelioma. Abdominal ultrasonography and computed tomographic scan revealed multiple low density areas in the liver. Eleven years later, a metastatic lesion was found in the thoracic spine at the level of Th7-8. The histologic findings were basically similar to those of the left neck mass. However, because of the presence of Kp-1-positive multinucleated osteoclast-like giant cells throughout the tumor, the thoracic lesion was diagnosed as an epithelioid hemangiothelioma with osteoclast-like giant cells. This unique form of epithelioid hemangioendothelioma is extremely rare and should be distinguished from other benign and malignant tumors with osteoclast-like giant cells.