Abstract: | Ultrastructural study of five typical lesions of dermatofibrosarcoma protuberans revealed that the basic cell is fusiform and has a somewhat indented nucleus and an even distribution of cytoplasmic organelles. Fragments of basal lamina, intercellular junctions, abundant intercellular fibers, and a tendency to form cellular sheaths also were found. The tumor cells had a strong resemblance to pericytes and perineural cells, as well as marked ultrastructural similarities to neurofibroma. The authors conclude that dermatofibrosarcoma protuberans arises from a primitive fibroblastic cell with a "sheath forming cell" differentiation that has a closer relationship to the perineural cell than to the pericyte. |