Proliferating trichilemmal cyst with focal invasion - Report of a case anda review of the literature

Proliferating trichilemmal cyst (PTC) is a rare but morphologically distinc tive tumor that usually occurs in the scalp of elderly women. Furthermore. only 30 well-documented examples of so-called malignant PTC have been repor ted. Alternatively, some authors have recently proposed that PTC is squamou s cell carcinoma. We describe a case of PTC with focal invasion that was in distinguishable from squamous cell carcinoma in areas, and we review the li terature. This debate should be considered in PTCs to provide adequate trea tment (wide local excision) and follow-up (long term), particularly in larg e and longstanding lesions.