title: A multiobserver, population-based analysis of histologic dysplasia in melanocytic nevi.
abstract: BACKGROUND
  Nevi that are clinically atypical and histologically dysplastic have been associated with increased melanoma risk. There are few reproducibility studies or population-based studies of nevus histology.
  
  
  OBJECTIVE
  Our purpose was to quantify concordance in histologic diagnosis of melanocytic lesions among a diverse group of pathologists, to assess intraobserver concordance by comparing readings of the same slide as well as of adjacent recuts from the same block, to correlate histology with nevus appearance and melanoma risk, and to estimate the range of prevalence of histologic dysplasia.
  
  
  METHODS
  Histologic slides were prepared from 149 tissue blocks of pigmented lesions from melanoma cases, relatives, and controls. Six dermatopathologists independently evaluated the lesions for histologic dysplasia, without prior agreement on criteria.
  
  
  RESULTS
  According to kappa statistics, intraobserver reproducibility was substantial, and interobserver concordance was fair, despite differences in criteria. The estimated prevalences of histologic dysplasia for the six pathologists ranged from 7% to 32%. Histologic dysplasia was correlated with nevus size for most observers, confounding the observed correlation between nevus appearance and histology.
  
  
  CONCLUSIONS
  Although experienced dermatopathologists use different diagnostic criteria for histologic dysplasia, their usage is consistent. Histologic changes ascribed to melanocytic dysplasia are prevalent in the white population for all pathologists. The term nevus with histologic dysplasia should be used in preference to dysplastic nevus.
authors.affiliation: Department of Internal Medicine (Dermatology), University of Utah School of Medicine, Salt Lake City.
authors.forename: M W
authors.initials: MW
authors.lastname: Piepkorn
authors.forename: R L
authors.initials: RL
authors.lastname: Barnhill
authors.forename: L A
authors.initials: LA
authors.lastname: Cannon-Albright
authors.forename: D E
authors.initials: DE
authors.lastname: Elder
authors.forename: D E
authors.initials: DE
authors.lastname: Goldgar
authors.forename: C M
authors.initials: CM
authors.lastname: Lewis
authors.forename: J C
authors.initials: JC
authors.lastname: Maize
authors.forename: L J
authors.initials: LJ
authors.lastname: Meyer
authors.forename: M S
authors.initials: MS
authors.lastname: Rabkin
authors.forename: R W
authors.initials: RW
authors.lastname: Sagebiel
mesh_terms: D000328:Adult; D012628:Dermatitis, Seborrheic / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D007911:Lentigo / Q000453:epidemiology / Q000473:pathology; D008297:Male; D008545:Melanoma / Q000453:epidemiology / Q000473:pathology; D008875:Middle Aged; D009508:Nevus, Pigmented / Q000453:epidemiology* / Q000473:pathology*; D015588:Observer Variation; D011159:Population Surveillance; D015995:Prevalence; D015203:Reproducibility of Results; D012878:Skin Neoplasms / Q000453:epidemiology* / Q000473:pathology*