Trichofolliculoma

Trichofolliculoma is a cutaneous adnexal tumor derived from the hair follicle. Trichofolliculomas, sometimes called folliculomas, are a category of benign hair follicle tumors comprising a diverse group of uncommon neoplasms. The specific type and extent of hair follicle differentiation distinguish each neoplasm. Several examples of more widely documented benign hair follicle tumors include trichilemmoma, trichoadenoma, dila­ted pore of Winer, and trichoblastoma .

Trichofolliculomas are considered hamartomatous neoplasms rather than cancerous. Trichofolliculomas generally are characterized by well-differentiated cells without atypical features that display abnormal tissue arrangement. More specifically, trichofolliculomas manifest a cystic dilation of one or multiple infundibula with a centralized opening to the skin surface, through which one or more hair shafts pass.