[Proliferating trichilemmal tumor of the ischiorectal fossa]. / Tumeur trichilemmale proliférante de la région ischio-rectale.

Proliferating trichilemmal tumor (PTT) is rare and follows a protracted course, almost always benign. Nevertheless an adverse outcome may occur. Usually PTT presents as an indolent mass in the scalp of elderly women. We report a case of PTT localized in the ischiorectal fossa, which might have been diagnosed as an epidermoid carcinoma.