Desmoplastic Trichilemmoma

Trichilemmomas typically present as solitary lesions on the face but when multiple can be associated with Cowden syndrome. The typical histologic features as seen in this case are: overall circumscription, endophytic growth, peripheral palisading, one or more connections to the epidermis, thickened basement membranes, glycogenated cuboidal cells with clear cytoplasm and round nuclei, squamous whorls and keratinization.