Diagnostic problems concerning epithelioid sarcoma--case analysis

We discuss here five cases of epithelioid sarcoma (ES) with final diagnosis established after reexamination of initial findings. Problems with differential diagnosis of these neoplasms arise since their microscopic picture may simulate several other pathological conditions such as non-neoplastic granulomatous reactions, squamous cell carcinomas and adenocarcinomas, melanomas and soft tissue sarcomas with epithelioid component. Final ES diagnosis requires presence of cytokeratin, EMA and vimentin in neoplastic cells, as confirmed by immunohistochemical reactions. Differential diagnosis is also helped by concurrent cytology assessment that allows recognizing more easily such characteristic features as presence of plasmacytoid or spindle-shaped cells.