Clear cell sarcoma of tendons and aponeuroses (malignant melanoma of soft parts): report of 2 cases.

Clear cell sarcoma of tendons and aponeuroses (CCSTA, malignant melanoma of soft parts), first described by Enzinger in 1965, is a rare and slow-growing soft tissue tumor mainly affecting the extremities of young adults. The tumor is believed to be a tumor of melanocyte, although its histogenesis is not definitely established. Here we report 2 cases of CCSTA with typical clinical and pathological features. A tumor grew from the right ankle of a 32-year-old man (case 1) and from the left foot of an 18-year-old woman (case 2). The tumors were deep seated and intimately bound to tendons or aponeuroses without involvement of the overlying skin. Grossly, they were greyish white, variegated with brown or black patches. Histologically, the tumor cells were arranged in nests or fascicles and composed of fusiform or polygonal cells with clear cytoplasm. Ultrastructurally, they consisted of closely apposed cells with intracytoplasmic melanosomes. Case 1 was found to have distant metastases within 6 months and died 1 year later. Case 2 received postoperative radiotherapy and was free of recurrence or metastasis 14 months after operation. The treatment of CCSTA should include radical excision, radiotherapy, and chemotherapy. The prognosis is poor.