title: A nongrading histologic approach to Clark (dysplastic) nevi: A potential to decrease the excision rate.
abstract: BACKGROUND
  Despite a lack of evidence that dysplastic nevi are precursors to melanoma, a large proportion of dermatologists continue to treat them as such. Emerging data suggest that histologic grading approach may result in many unnecessary excisions.
  
  
  OBJECTIVE
  Using a nongrading approach to diagnosis of Clark/dysplastic nevi, the current study sought to define and determine the diagnostic uncertainty rate, and to report on the results of re-excisions of such lesions.
  
  
  METHODS
  All melanocytic nevi submitted to an academic dermatopathology laboratory between January 1, 2007, and December 31, 2013, were categorized. The number of Clark nevi recommended for re-excision divided by the total number of Clark nevi was taken to be the diagnostic uncertainty rate.
  
  
  RESULTS
  This nongrading approach resulted in an excision recommendation/diagnostic uncertainty rate of 11.1%. In 2% of the excised specimens, the diagnosis was changed to melanoma.
  
  
  CONCLUSIONS
  The study was performed at a single institution, and assigned diagnoses could not be verified other than by the diagnosing dermatopathologists. Lesions that were not submitted as re-excision specimens could have altered the results had they been available for evaluation.
  
  
  CONCLUSIONS
  Compared with previously reported excision rates, the current study shows that the nongrading approach to Clark nevi results in a lower excision rate while still maintaining a low rate of change in diagnosis similar to the grading approach.
authors.affiliation: Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Lozeau
authors.affiliation: Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Michele J
authors.initials: MJ
authors.lastname: Farber
authors.affiliation: Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania. Electronic address: jason.lee@jefferson.edu.
authors.forename: Jason B
authors.initials: JB
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D015331:Cohort Studies; D004416:Dysplastic Nevus Syndrome / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008545:Melanoma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D015580:Mohs Surgery / Q000379:methods / Q000706:statistics & numerical data*; D060787:Neoplasm Grading / Q000379:methods; D011230:Precancerous Conditions / Q000473:pathology* / Q000601:surgery; D058996:Quality Improvement; D012189:Retrospective Studies; D018570:Risk Assessment; D012878:Skin Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome
keywords: Clark nevus; atypia; biopsy; diagnostic uncertainty; dysplastic nevus; excision; melanoma