Epithelioid sarcoma.A sarcoma simulating a granuloma or a carcinoma

This article reviews the pathologic features and the behavior of 62 cases of a peculiar form of sarcoma that has repeatedly been confused with a chronic inflammatory processa necrotizing granulomaand a squamous cell carcinoma. The tumor occurs chiefly in young adults (median age 23 years) and most commonly affects the soft tissues of the handthe forearmand the pretibial region. It tends to grow in a nodular or multinodular manner along fascial structures and tendonsoften with central necrosis of the tumor nodules and ulceration of the overlying skin. Most of the tumors grow slowlyand many of our cases had been present for months or years prior to surgery. Microscopicallythe tumor consists of irregular nodular masses of largedeeply acidophilic polygonal cells merging with spindle cellsfrequently associated with large amounts of hyalinized collagen. Follow-up information on 54 patients (87%) revealed slowrelentless clinical course with frequent recurrence (85%) and late metastasis (30%). Cure may be achieved by wide local excision at early stage of disease.