Clear cell sarcoma: report of two cases with ultrastructural observations and review of the literature.

Two cases of clear cell sarcoma of tendons and aponeuroses, one with prominent melanogenesis, are reported. One tumour arose in the left buttock of a young male and the other in the left fourth toe of a young female. Both had a rapid fatal course with local and distant metastases. Electron microscopy shows melanosomes in one case, suggesting a melanotic origin.