title: Surgical margins for melanoma in situ.
abstract: BACKGROUND
  A controversy in the treatment of melanoma in situ is the required width of surgical margin. The currently accepted 5-mm margin is based on a 1992 consensus opinion, despite data since then showing this is inadequate.
  
  
  OBJECTIVE
  We sought to develop guidelines for predetermined surgical margins for excision of melanoma in situ.
  
  
  METHODS
  A prospectively collected series of 1072 patients with 1120 melanoma in situs was studied. All lesions were excised by Mohs micrographic surgery with frozen-section examination of the margin. The minimal surgical margin was 6 mm, and the total margin was calculated by adding an additional 3 mm for each subsequent stage required. The minimum surgical margin that would successfully remove 97% of all tumors was calculated. Local recurrence was also tabulated.
  
  
  RESULTS
  In all, 86% of melanoma in situs were successfully excised with a 6-mm margin; 9 mm removed 98.9% of melanoma in situs. The superiority of 9-mm to 6-mm margins was significant (P < .001). Gender, location, and diameter did not affect results. Recurrence rate for this set of patients treated with Mohs micrographic surgery was 0.3% (n = 3).
  
  
  CONCLUSIONS
  Margins less than 6 mm were not studied. This is a referral center for melanoma in situ and 10% of tumors were previously treated before presentation to our clinic.
  
  
  CONCLUSIONS
  The frequently recommended 5-mm margin for melanoma is inadequate. Standard surgical excision of melanoma in situ should include 9 mm of normal-appearing skin, similar to that recommended for early invasive melanoma.
authors.affiliation: Zitelli and Brodland, Pittsburgh, Pennsylvania 15232, USA. Joy444@gmail.com
authors.forename: Joy H
authors.initials: JH
authors.lastname: Kunishige
authors.forename: David G
authors.initials: DG
authors.lastname: Brodland
authors.forename: John A
authors.initials: JA
authors.lastname: Zitelli
mesh_terms: D000368:Aged; D001706:Biopsy / Q000592:standards; D002278:Carcinoma in Situ / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D005629:Frozen Sections / Q000592:standards; D006801:Humans; D018327:Hutchinson's Melanotic Freckle / Q000401:mortality / Q000473:pathology / Q000601:surgery; D008297:Male; D008545:Melanoma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D015580:Mohs Surgery / Q000379:methods* / Q000401:mortality / Q000592:standards*; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000517:prevention & control; D011183:Postoperative Complications / Q000401:mortality / Q000517:prevention & control; D017410:Practice Guidelines as Topic / Q000592:standards*; D011446:Prospective Studies; D012878:Skin Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome