title: Trichoadenoma of the upper lip.
abstract: BACKGROUND
  Trichoadenoma of Nikolowski, who describe the first cases in 1958, is a rare and benign tumor of the hair follicle. It is well-differentiated and slowly-growing. The clinical appearance of Trichoadenoma (TA) can be similar to basal cell carcinoma or epidermal cyst.
  
  
  RESULTS
  We describe a 44-year-old male who was referred for nodular lesion on the upper lip and a TA was diagnosed. Oral examination showed exophytic yellow mass located between mucous membrane of the upper lip and vestibular gingiva, 1.2 per 0.8 cm. Anamnestic data was non-contributory. An excisional biopsy of the lesion was performed. Microscopically, the lesion consisted of multiple keratinous cysts lined with stratified squamous epithelium and intermingled with solid islands of basaloid cells lying within sclerotic stroma. The pathological diagnosis was TA. The surgical wound healed uneventfully.
  
  
  CONCLUSIONS
  Because the lesion is unique, it is uncertain how aggressive or indolent the tumor might be. Therefore, the microscopical analysis is mandatory. At the best of our knowledge, this is the second case of trichoadenoma of the lip.
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, Ospedale Maggiore Policlinico Fondazione Ca' Granda IRCCS, University of Milan, Via Della Commenda 10, 20122 Milan, Italy. gpbombeccari@libero.it.
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Bombeccari
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Guzzi
authors.forename: Umberto
authors.initials: U
authors.lastname: Mariani
authors.forename: Andrea
authors.initials: A
authors.lastname: Gianatti
authors.forename: Diego
authors.initials: D
authors.lastname: Ruffoni
authors.forename: Franco
authors.initials: F
authors.lastname: Santoro
authors.forename: Francesco
authors.initials: F
authors.lastname: Spadari
mesh_terms: D000328:Adult; D004814:Epidermal Cyst; D006201:Hair Diseases / Q000175:diagnosis*; D018859:Hair Follicle; D006801:Humans; D008046:Lip; D008048:Lip Neoplasms / Q000175:diagnosis*; D008297:Male; D012878:Skin Neoplasms / Q000175:diagnosis*