Multiple familial trichoepitheliomas: a folliculosebaceous-apocrine genodermatosis.

We reviewed the pathologic findings on a family with multiple hereditary trichoepitheliomas. Although the majority of the lesions were trichoepitheliomas, basal cell carcinomas, spiradenomas, and spiradenomas with cylindromatous foci (spiradenocylindroma) were present, representing a spectrum of lesions exhibiting folliculosebaceous (trichoepithelioma, basal cell carcinoma) and apocrine (spiradenoma, spiradenocylindroma) differentiation. Multiple familial trichoepitheliomas may be a syndrome whereby tumors develop from undifferentiated germinative cells of the folliculosebaceous-apocrine unit. Published findings regarding the genetics of this syndrome and solitary trichoepitheliomas are reviewed; although the molecular basis for the tumors has yet to be determined, current data suggest that a tumor suppressor gene may be involved.