malignant mesenchymal tumor showing nodular, granulomalike growth of eosinophilic epithelioid and spindle cells palisading around the centrally located necrotic areas. Two subtypes are recognized: a classical distal and a fibromalike form. Tumors typically occur in the subcutaneous tissue along the tendons and fascia.
epithelioid sarcomaA rare, low-grade sarcoma, which primarily affects the distal extremities, especially the hand and fingers. Male:female ratio, 2:1, affecting patients age 10–35 if distal and older if proximal.
Benign fibrous histiocytoma, fibromatosis, granuloma annulare, infectious granuloma, myositis ossificans, necrobiosis lipoidica, necrobiotic granuloma, nodular fasciitis, rhabdoid tumour, rheumatoid nodule.
Adnexal carcinoma, clear-cell carcinoma, epithelioid vascular neoplasm, fibrosarcoma, melanoma, metastatic carcinoma, squamous cell carcinoma, synovial sarcoma.
Wide local excision or amputation.
Recurrence in 35–75%; 40–45% metastasise—e.g., to lung, regional lymph nodes, scalp; 5-year survival in 80%; 10-year survival in 50%.
Deep, > 5 cm, high mitotic rate, vessel and nerve invasion, recurrence, nodal metastasis.
Epithelioid sarcoma types
Conventional (diffuse) form
Affects distal extremities, especially hand and fingers; male:female ratio, 2:1; affects patients age 10–35 if distal and older if proximal.
Older patients; more aggressive than conventional (distal) type; located deep in the pelvis, perineum, pubis, vulva and penis.
Large epithelioid cells with marked atypia and prominent nucleoli, varying amounts of rhabdoid features.