Spindle cell hemangioendothelioma: report of three cases.

Three cases of spindle cell hemangioendothelioma were studied. Two had multiple nodules and the third had a single, recurrent lesion in the dermis or subcutis of the distal extremities. The tumor initiated at the age of 3 months in one patient and at the ages of 11 or 12 years in the remaining two. Local recurrence after surgical excision was observed in all cases. Microscopically the tumors were composed of two components; cavernous blood spaces and a proliferation of spindle cells. Among these spindle cells, there were occasional epithelioid endothelial cells with intracytoplasmic lumina. Phleboliths were observed in two cases. Most of the endothelial cells lining the cavernous spaces were positive for factor VIII-associated antigen in all cases; the intracytoplasmic lumina were also positive in two cases. The spindle cells were negative for that antigen in all cases. However, they were positive for desmin in one case. Electronmicroscopically, the spindle cells resembled primitive mesenchymal cells.