Epithelioid sarcoma-like hemangioendothelioma: a clinicopathologic and immunohistochemical study of 3 cases
To study the clinicopathologic features and differential diagnosis of epithelioid sarcoma-like hemangioendothelioma (ES-H). The clinical, radiologic and pathologic features of three cases of ES-H were analyzed. All the 3 cases occurred in male adults. The age ranged from 44 to 53 years. The presentations included left neck mass, iliac pain and bilateral shoulder masses. Histologically, ES-H was composed of a mixture of spindle and epithelioid tumor cells. Transition between the two cell types was demonstrated. The tumor cells were arranged in compact sheets, vague nodules or intersecting fascicles, amongst a collagenous stroma. Central coagulative necrosis was identified in one case, reminiscent the morphology that seen in epithelioid sarcoma. There was no evidence of angiogenesis, though focal presence of intracytoplasmic vacuoles was seen in one case, as in classic examples of epithelioid hemangioendothelioma. Immunohistochemical study showed that the tumor cells expressed both epithelial (AE1/AE3, CAM5.2 and epithelial membrane antigen) and endothelial (CD31, Fli-1 and factor VIII-related antigen) markers. Two of the cases were also positive for CD34. All of the patients were treated by surgical resection. Two patients remain well at 14-month and 9-month follow up, respectively. The remaining patient had repeated local recurrences during a 6-year period. ES-H represents a rare morphologic type of hemangioendothelioma. It has some overlapping histologic features with epithelioid sarcoma and epithelioid hemangioendothelioma. The endothelial nature of ES-H is difficult to be verified on the basis of morphologic examination alone. Confirmation of the diagnosis with immunohistochemistry is necessary. ES-H is likely related to epithelioid hemangioendothelioma and may represent a cellular spindle cell variant of epithelioid hemangioendothelioma.