title: Natural history of dysplastic nevi.
abstract: BACKGROUND
  Dysplastic nevi are markers of melanoma risk and potential precursors of melanoma. Few studies have addressed the natural history of dysplastic nevi.
  
  
  OBJECTIVE
  Our purpose was to describe the changes observed in nevi over time in a cohort of our patients with dysplastic nevi.
  
  
  METHODS
  We used a historical cohort design to study 153 patients with dysplastic nevi observed for a minimum of 5 years. Physical examination at completion of the study was compared with baseline overview and close-up photographs. Lesions excised during the study interval were assessed for history of change.
  
  
  RESULTS
  Fifty one percent of all evaluated nevi (297 of 593) showed clinical signs of change during an average follow-up of 89 months. New nevi were common in adulthood and continued to form in more than 20% of patients older than 50 years of age. Nevi were observed to become more clinically atypical, less clinically atypical, and disappear in all age groups. In this small cohort rates of nevus change were not correlated with personal or family history of melanoma, sex, or total number of nevi. Total nevus counts and rates of nevus change were correlated with age.
  
  
  CONCLUSIONS
  Dysplastic nevi remain clinically dynamic in adulthood. Our data suggest that the decrease in counts of dysplastic nevi associated with increasing age is only partly explained by the disappearance of nevi over time and probably reflects a tendency to larger numbers of nevi among more recent birth cohorts.
authors.affiliation: Department of Dermatology, University of Pennsylvania, Philadelphia 19104.
authors.forename: A C
authors.initials: AC
authors.lastname: Halpern
authors.forename: D
authors.initials: D
authors.lastname: Guerry
authors.forename: D E
authors.initials: DE
authors.lastname: Elder
authors.forename: B
authors.initials: B
authors.lastname: Trock
authors.forename: M
authors.initials: M
authors.lastname: Synnestvedt
authors.forename: T
authors.initials: T
authors.lastname: Humphreys
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D015331:Cohort Studies; D004416:Dysplastic Nevus Syndrome / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008545:Melanoma / Q000235:genetics / Q000473:pathology; D008875:Middle Aged; D009365:Neoplasm Regression, Spontaneous / Q000473:pathology; D009378:Neoplasms, Multiple Primary / Q000473:pathology; D011446:Prospective Studies; D012307:Risk Factors; D012878:Skin Neoplasms / Q000473:pathology*