title: Mohs surgical extirpation of a basal cell carcinoma in a patient with familial multiple trichoepitheliomas.
abstract: BACKGROUND
  The success of Mohs surgery relies on the ability to histologically differentiate tumor from the normal background tissue of the patient. In most cases of basal cell carcinoma and nonmelanoma skin cancer, this is a relatively straightforward process. However, in distinction, when only subtle histopathologic features differentiate the background tissue from the tumor of interest, the determination of a tumor-free margin becomes more challenging.
  
  
  OBJECTIVE
  Our objective is to highlight the histopathologic features that we used to differentiate our patient's near-confluent background of trichoepitheliomas from the basal cell carcinoma that we were extirpating.
  
  
  METHODS
  Case report.
  
  
  RESULTS
  A 41-year-old white female with a history of familial multiple facial trichoepitheliomas presented for removal of a basal cell carcinoma on her right lower cutaneous lip. Mohs surgery was used to remove the tumor. The characteristic features of basal cell carcinoma and trichoepithelioma were used to differentiate the basal cell carcinoma that we were removing from the surrounding trichoepitheliomatous neoplasia.
  
  
  CONCLUSIONS
  Mohs surgical extirpation of a basal cell carcinoma in a patient with multiple familial trichoepitheliomas requires a clear understanding of the histopathologic features that differentiate a trichoepithelioma from a basal cell carcinoma.
authors.affiliation: Laser and Skin Surgery Center of New York, New York, New York 10016, USA.
authors.forename: Galen H
authors.initials: GH
authors.lastname: Fisher
authors.forename: Joan
authors.initials: J
authors.lastname: Mones
authors.forename: Melissa
authors.initials: M
authors.lastname: Gill
authors.forename: Julide Tok
authors.initials: JT
authors.lastname: Celebi
authors.forename: Roy G
authors.initials: RG
authors.lastname: Geronemus
mesh_terms: D000328:Adult; D002280:Basal Cell Carcinoma / Q000235:genetics* / Q000473:pathology / Q000601:surgery*; D005153:Facial Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D015580:Mohs Surgery; D012878:Skin Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery*; D013524:Surgical Flaps