Korean Journal of Dermatology  1999;37(12):1853-1855

A Case of Trichilemmal Horn .

Hoon KANG 1 ; Sang Jung LEE ; Sang Hyun CHO ; Young Min PARK

Affiliations

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Keywords

Trichilemmal horn; Trichilemmal keratinization

Country

Republic of Korea

Language

Korean

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.