title: Trichilemmal horn on burn scar tissue.
abstract: We describe the case of a 53-year-old Japanese woman with a trichilemmal horn on burn scar tissue on her left arm. When examined using light microscopy, the lesion showed U-shaped epidermal proliferations which keratinized in a fashion either identical or similar to trichilemmal keratinization. Immunohistochemical results established a relationship between the trichilemmal horn and the outer root sheath of the hair follicle. Trichilemmal keratinization was observed using electron microscopy. Apparently, the tumor had developed on a skin scar where hair follicles were not clinically present. We concluded that the tumor had originated from some hair follicle cells remaining in the epidermis after the burn.
authors.affiliation: Department of Dermatology, Surugadai Nihon University Hospital, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8309 Japan. mkano@med.nihon-u.ac.jp
authors.forename: Mieko
authors.initials: M
authors.lastname: Kudo
authors.forename: Shuhko
authors.initials: S
authors.lastname: Uchigasaki
authors.forename: Shunichi
authors.initials: S
authors.lastname: Baba
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D001132:Arm; D002056:Burns / Q000473:pathology*; D002921:Cicatrix / Q000473:pathology*; D005260:Female; D018859:Hair Follicle / Q000473:pathology*; D006801:Humans; D007642:Keratosis / Q000473:pathology*; D008875:Middle Aged