Oral granular-cell tumors. Report of twenty-five cases with electron microscopy.

Twenty-five cases of granular-cell tumor of the oral cavity are reported. The clinical findings are similar to previously published data. Of five cases studied by electron microscopy, three were processed directly from fresh surgical specimens and two cases were processed following initial formalin fixation. The granules for the most part are morphologically compatible with lysosomes except for a single variety containing viruslike particles. There is increasing evidence in support of a neural origin, but the indications are that more than one cell type may be the progenitor of granular cells of the granular cell tumor.