Cutaneous Clear Cell Sarcoma in the Genital Region: A Report of Two Cases at an Unusual Location

Clear cell sarcoma (CCS) is a rare sarcoma that typically arises in the deep soft tissue of the extremities. We describe two patients with molecularly confirmed CCS in genital skin. Patient 1 was a 22-year-old woman with a vulvar mass, and Patient 2 was a 25-year-old man with a scrotal plaque. Histopathological examination in each case revealed a cellular tumor distributed in nests and sheets, composed of epithelioid and spindled cells. The tumor cells exhibited clear and eosinophilic cytoplasm, vesicular nuclei, and prominent nucleoli. Immunohistochemical analysis demonstrated that both tumors expressed Sox10 and HMB45. FISH testing revealed EWSR1 rearrangements in both cases, and further NGS analysis in Case 1 confirmed the presence of an EWSR1-ATF1 fusion. To date, only 3 cases of CCS have been reported involving the genital region, all originating in deep soft tissues. Our report expands the known anatomical sites of cutaneous clear cell sarcoma involvement.