[Malignant proliferating trichilemmal cyst of the scalp: A case report]

Proliferating trichilemmal cyst (PTC) is a rare adnexal tumor, generally benign, primarily sitting on the scalp of elderly women. About fifty cases are reported in the literature. Herein, we describe another one particularly aggressive.

A 70-year-old woman had been showing an increase in the size of an occipital cyst for 6years. A cephalic scan and wide surgical excision had confirmed the diagnosis of a malignant PTC. Four months later, the tumor recurred with regional metastases and intracerebral invasion.

Through our case and based on the literature analyzing, we discuss the nosology of PTC and its clinical and histological distinctive elements.

Large studies are needed to better understand the specificities of PTC, specially malignant form, but it remains difficult because of its rarity.