Clear cell sarcoma.

Malignant melanoma (MM) of soft tissue, also called clear cell sarcoma (CCS) of tendons and aponeuroses, derives from the neural crest. CCS is similar morphologically to MM but has no precursor skin lesion, and instead, has a characteristic chromosomal translocation. Prognosis is related to the tumor size. Early recognition and initial radical surgery is the key to a favorable outcome. The tumor has to be differentiated from other benign and malignant lesions of the soft tissues, such as fibrosarcoma. The demonstration of melanin and a positive immunohistochemical reaction for S-100 protein and HMB-45 can assist in the differential diagnosis. We report the case of a 58-year-old woman with CCS arising from the soft tissue of her little finger.