Proliferating Pilar Tumor in an Atypical Location.

Proliferative pilar tumors are rare skin neoplasms with very few reported cases and, therefore, limited evidence. They derive from the outer root sheath of the hair follicle and usually manifest as a benign lesion although rarely they can become malignant. Macroscopically, they can be confused with a squamous cell carcinoma, being the histopathological assessment the main diagnostic tool to differentiate them. The aim of this case report is to present a case of malignant proliferative pilar tumor in an atypical location, as well as to describe the diagnostic and therapeutic approach. In this work, we highlight the importance of early histopathological diagnosis and timely surgical treatment.