Sarcoma epitheloides C49.9

Enzinger, 1970

Very rare, aggressively growing malignant tumor of the soft tissues, which appears as a deep dermal or subcutaneous plate-like or nodular mass.

The epithelioid sarcoma is divided:

• classic epithelioid sarcoma: subcutaneous or deep dermal, nodular neoplasm of the distal extremities (hands, fingers, lower limb) of young adults
• proximal epithelioid sarcoma: deep soft tissue of the pelvis and genital region (e.g. vulva) of elderly patients, with a significantly worse prognosis.

Mostly multilocular solid tumor nodes with epitheloid or even spindle cell formations; central necrobiosis zones are frequent. Also calcifications or myxoid stroma reactions. Mitoses are rarely detectable. The tumour cells express vimentin, EMA, pancytokeratin. Rare expression of CD34 and the vascular marker ERG. Muations of the SMARCB1/INI gene located on chromosome 22q1-2 are detectable.

Operatively with sufficient safety distance.

High postoperative recurrence rate. Lymph node metastases are expected in 40-50% of epithelioid sarcomas. The 5-year survival rate is 60-80%.

1. Gayatri SP et al (2015) Proximal type of epithelioid sarcoma of back with metastasis to humerus at presentation: Indicating aggressive behavior. Indian J Cancer 52: 97-98.
2. Kohashi K et al (20149 ERG and SALL4 expressions in SMARCB1/INI1-deficient tumors: a useful tool for distinguishing epithelioid sarcoma from malignant rhabdoid tumor. Hum Pathol 46: 225-230.
3. Menztel T (2016) Mesenchymal tumors of the skin. In: Cerroni L et al. histopathology of the skin. Springer-Verlag Berlin Heidelberg New-York S788-789
4. Rodrigues AI et al (2015) Proximal-type epithelioid sarcoma-unusual presentation: unilateral vulvar mass. BMJ Case Rep doi: 10.1136/bcr-2014-208488.
5. Thway K et al (2016) Epithelioid Sarcoma: Diagnostic Features and Genetics. Adv Anat Pathol 23:414-9