Ultrastructural study of a clear cell sarcoma suggesting schwannian differentiation

A clear cell sarcoma that developed on the left back of a 19-year-old Japanese female was studied ultrastructurally. The findings included basal laminae, desmosomelike junctions, cytoplasmic interdigitations, lamellar bodies, and immature melanosomes. These findings suggest schwannian differentiation of this tumor, since they are not usual features of malignant melanoma except for melanosomes. Therefore this tumor seems to be more akin to malignant schwannoma than to malignant melanoma.