Plexiform granular cell tumor. A report of two cases.

A previously undescribed variant of granular cell tumor with an interesting plexiform pattern was found in the lower leg of a 10-year-old girl and on the back of a 12-year-old girl. Clinically, the patients presented with intradermal plaques that were accompanied by variable degrees of pain or tenderness. Histopathologic examination revealed granular cell tumors with various sized fascicles, particularly around nerve bundles, in a plexiform pattern. Cytoplasmic granules were PAS positive. Immunohistochemical studies showed tumor cells to be strongly positive with S-100 protein and weakly positive with alpha-1-antichymotrypsin and vimentin. These findings offer further support for a neural origin for granular cell tumors.