EPITHELIOID SARCOMA

Epithelioid sarcomas are the most common soft tissue sarcoma of the hand.  These lesions are rare, malignant, slow-growing soft-tissue tumors.  They are often misdiagnosed as benign cutaneous or subcutaneous lesions or ulceration that can masquerade as an infectious process. They are commonly located in the upper extremities of young adults and have a tendency for local recurrence. Epithelioid tumors frequently metastasize to the lungs and lymph nodes.^1-6

Pathophysiology

• Tumor of lineage and uncertain differentiation
• Displays carcinoma-like epithelial differentiation
• Predominantly solid, multinodular mass with multiple areas of hemorrhage and necrosis
• Nodules in deep soft tissue, less frequently in skin or subcutis

Related Anatomy

• Predominantly on forearm, dorsum of the hand, palm or finger. ⁶  

Incidence and Related Conditions

• More common in men than in women (2:1)
• Estimated annual incidence of upper extremity epithelioid sarcoma was 0.4 cases per 1 million individuals in 2005
• Metastasizes in about 40% of patients to the lungs (predominantly), lymph nodes, bone and brain

Differential Diagnosis ^1-6

• Chronic granulomatous inflammation
• Fibrous histocytoma
• Nodular fasciitis
• Fibromatosis
• Giant cell tumor of tendon sheath
• Melanoma
• Clear-cell sarcoma of the tendon and aponeurosis
• Schwannoma
• Metastatic squamous cell carcinoma
• Metastatic adenocarcinoma
• Synovial sarcoma
• Epithelioid hemagnioendothelioma
• Epithelioid leiomyosarcoma
• Malignant extrarenal rhabdoid tumors
• Epithelioid vascular neoplasm
• Amelanotic melanoma
• Angiosarcoma
• Fibrosarcoma
• Malignant fibrous histiosarcoma
• Low grade chronic infection
• Verruca vulgaris (wart)
• Unhealed wound 

A typical patient may report a small painless hand mass that increases in size and begins to ulcerate the skin.  The patient may have been treated for several different benign cutaneous conditions and have had a dermatologic biopsy which ultimately confirmed a sarcoma hisiologically.  Epithelioid sarcoma is an aggressive neoplasm that can recur after excision and may metastasize prior or after surgical excision. 

• Excisional biopsy with incomplete (not clear) margins
• Incomplete workup or staging of the sarcoma and metastatic disease.
• Therefore, transfer to a specialist center is essential for soft tissue masses of uncertain identity.

• Depending on adequacy of initial excision, recurrence rate of 34–77%  and metastases in about 40% of the patients, primarily involving the lungs ^1-6
• Median overall survival is about 88 months for patients without distant metastases and months for patients with distant metastases
• Prognosis affected by site, age of diagnosis, tumor size, staging, and microscopic pathology

• Epithelioid sarcoma is the most common soft tissure sarcoma of the hand.^1-6
• Tumors can look like infections and infections can look like tumors; therefore, it essential to culture and biopsy all suspicious lesions!
• Because the differential diagnosis is vast, epithelioid sarcoma may be discovered incidently after a dermatologic or excisional biopsy of a suspected benign lesion.
• Be extra cautious when evaluating and treating a hand mass with a chronic ulceration of the skin.
• These lesions require pathologic analysis and diagnostic stains for those characteristic immunophenotypes associated with epithelioid sarcoma.
• Characteristic immunophenotype analysis should include stains for vimentin, cytokeratin, keratin, epithelial membrane antigen.
• Genetic evaluation may include a loss of INI1 gene (>80% of patients with epithelioid sarcoma)

Cited and New Articles

1. Guzzetta A, Montgomery E, Lyu H et al. Epithelioid sarcoma: one institution's experience with a rare sarcoma. J Surg Res 2012;177(1):116-22. PMID: 22575361
2. Akpinar F, Dervis E, Demirkesen C, et al. Ind J Dermatol Venereol Leprol 2014;80(2):168-70. PMID: 24685864
3. Levy, A, Le Péchoux C , Terrier P, et al. Epithelioid sarcoma: need for a multimodal approach to maximize the chances of curative conservative treatment. Ann Surg Oncol2014;21(1):269-76. PMID: 24046109
4. Mavrogenis AF, Panagopoulos GN, Angelini A, Lesensky J, Vottis C, Megaloikonomos PD, Kokkalis ZT, Kontogeorgakis V Ruggieri P, Papagelopoulos PJ. Tumors of the hand. Eur J Orthop Surg Traumatol 2017; 27: 747-762. PMID: 28585186

1. Ross HM, Lewis JJ, Woodruff JM, Brennan MF. Epithelioid Sarcoma: clinical behavior and prognosis factors of survival. Ann Surg Onc 1997; 4(6): 491-495. PMID: 9309338
2. Athanasian EA. Malignant bone and soft-tissue sarcomas of the hand. J Hand Surg Am 2004; 4(2): 60-72.

Reviews

1. Armah H, Parwani A. Epithelioid sarcoma. Arch Pathol Lab Med2009;133(5):814-9. PMID: 19415960
2. Sobanko J, Meijer L, Nigra T. J Clin Aesthet Dermatol 2009;2(5):49-54. PMID: 20729965   

Classics

1. Enzinger F. Epitheloid sarcoma. A sarcoma simulating a granuloma or a carcinoma. Cancer 1970;26(5):1029-41. PMID: 5476785
2. Chase D, Enzinger F. Epithelioid sarcoma: Diagnosis, prognostic indicators, and treatment. Am J Surg Pathol 1985;9(4):241-63. PMID: 4014539