Epithelioid sarcoma:a clinicopathologic analysis of 5 cases

Objective To study clinical pathologic characteristics,diagnostic criteria and differential diagnosis of epithelioid sarcoma. Methods Clinical pathologic features were studied in 5 cases of epithelioid sarcoma with review of the literatures. Results 5 cases were surgical-removed specimens,located at limbs. The tumors showed a markedly nodular mass. Two kinds of tumour cells were identified:one was large polygonal or ovate cell with abundant eosinophilic cytoplasm,similar to epithelioid cell,and another spindle cell,or fibroblast-like cell. The two kinds of cells had gradual transition. The immunohistochemistry of tumor cells showed that the positive rates of vim,CK,EMA,CD34,S100 were 5/5,4/5,4/5,2/5 and 1/5,respectively. Conclusions Epithelioid sarcoma is a rare tumor of soft tissue. It is not difficult to diagnose the tumor with typical morphology,but for small biopsy or those with atypical histologic and immunohistochemical features,especially with less or without central necrosis in the neoplastic nodules,are easy to be confused with synovial sarcoma,epithelioid hemangioendothelioma,epithelioid malignant peripheral nerve sheath tumor and malignant melanoma,and diagnosis can be made with caution by combination of clinical data,microscopic characteristics and immunohistochemical findings.