A Case of Trichilemmal Horn / 대한피부과학회지

ABSTRACT

Trichilemmal horn is a unique, uncommon epidermal tumor that exhibits a hard protruding hyperkeratotic plaque. Histologically, it is characterized by striking orthokeratotic hyperkeratosis and verrucous hyperplasia of the epidermis without the formation of a granular cell layer. The acanthotic epidermis shows an epithelial lobule, composed of pale staining keratinocytes, that is contiguous with the overlying epithelium and extended into the dermis. We herein report a case of trichilemmal horn developing on the right temporal area of a 80-year-old woman, which shows typical clinical and histopathological features.