Epithelioid hemangioendothelioma. A rare tumor with variable prognosis presenting as a pleural effusion.

The chest x-ray film a 22-year-old man showed a large right-sided pleural effusion that was grossly hemorrhagic when aspirated. A computerized tomographic scan showed a complex mass with cystic components contiguous with the diaphragm. On thoracotomy the mass was found to be arising from the diaphragm and had the consistency of an organizing hematoma. Pathologic studies showed the mass to be an epithelioid hemangioendothelioma. This rare tumor has never been reported previously as arising from the diaphragm. It has a variable prognosis, but surgery remains the treatment of choice. In this report, we review the clinical and pathologic characteristics of this unusual tumor, as well as the distinctive roentgenographic findings with which it presented.