Epithelioid sarcoma
Overview
Rare soft tissue tumor of young adults of unknown histogenesis, predominantly occurring in the distal extremities, with characteristic morphologic features such as epithelioid cytology and a granuloma-like pattern.
Diagnosis
Epithelioid sarcoma is usually located on the distal extremities (hands, fingers and forearm). This tumour rarely occurs on the pelvis, perineum and vulva. The tumour spreads along fascial and neurovascular structures with formation of satellite nodules. Multiple recurrences are known to occur in this tumour. Metastasis to the scalp, lymphnode and lungs occur frequently. Adequate treatment requires early radical excision or amputation if the tumour is located in the fingers or toes. Regional lymphnode dissection should be included as lymphnode metastasis is common in epithelioid sarcoma. Surgical excision is combined with radiotherapy. Diagnosis is often delayed because of the unusual nature of the tumor.
Prognosis
More aggressive clinical course associated with: * proximal or axial tumor location * increased size * increased depth * hemorrhage * mitotic figures * necrosis * rhabdoid features * vascular invasion31,32
Treatment
Treatment: - despite its slow growth, the aggressive nature of tumor is evidence that 85% recurrence after local excision and 30% have metastasized; - note that epithelioid sarcoma can spread via lymph nodes, which impacts on prognosis; - other sarcomas which spread via lymph nodes include: clear cell sarcoma, synovial sarcoma, rhabdomyosarcoma; - recommended treatment is radical resection or amputation; - this is an aggressive tumor which may be found to metastasize even after years have passed;