Proliferating trichilemmal tumor of the vulva. Case report and review of the literature.

A case of proliferating trichilemmal tumor, otherwise known as pilar tumor, occurring in the dermis of the left labium majus of a 65-year-old woman, is presented. To our knowledge, this is the second reported case of such a tumor occurring in this location. The origin of this neoplasm, the reasons for its rarity at this site, and the range of its biological behavior are discussed in relation to the clinical manifestations of this case.