ABSTRACT
Tricholemmoma and tricholemmal carcinoma are benign and malignant tumors of the hair follicle, respectively. Described first by Headington and French in 1962, generally they are located on the head and neck of the elderly. Tricholemmoma clinically can occur as solitary or multiple flesh-topped and small papules. Multiple facial tricholemmomas are often associated with Cowden syndrome, a rare autosomal dominant genodermatosis characterized by the formation of multiple types of hamartomas and neoplastic growths. Tricholemmal carcinoma can occur as an exophytic or polypoid nodule. Dermoscopically, tricholemmoma shows keratin masses with perivascular whitish halos. Tricholemmal carcinoma shows a polymorphous vascular pattern, white-yellowish areas and ulceration.
Differential diagnoses for both tumors include basal cell carcinoma, squamous cell carcinoma, keratoacanthoma and viral warts.
