title: Constitutional intraepidermal ascent of melanocytes: a potential pitfall in the diagnosis of melanocytic lesions.
abstract: BACKGROUND
  Transepidermal melanocytic migration (TEM) is an important diagnostic criterion for malignancy, especially in association with cytologic atypia. However, TEM may also be observed in benign melanocytic tumors, such as Spitz nevus, acral nevi, or nevi in infancy. We discuss the value of TEM for the diagnosis of melanocytic tumors in a young patient previously diagnosed as having 11 cutaneous melanomas.
  
  
  METHODS
  A 17-year-old patient with a history of 11 cutaneous melanomas diagnosed in the past 3 years by different expert dermatopathologists presented in our department. The previous histological diagnoses of melanoma were mainly based on the presence of important TEM. A reevaluation of all histological specimens in light of the clinical context and the lack of genomic aberrations as detected by array-comparative genomic hybridization led to a revision of the previous diagnoses. The striking TEM observed represents, in our opinion, a constitutional element of the melanocytic nevi in this patient and not a marker of malignancy.
  
  
  CONCLUSIONS
  Awareness of this finding is important to avoid overdiagnosis of melanoma in cases of melanocytic nevi.
authors.affiliation: Department of Dermatology, University Hospital of Zurich, CH-8091 Zurich, Switzerland. katrin.kerl@usz.ch
authors.forename: Katrin
authors.initials: K
authors.lastname: Kerl
authors.forename: Werner
authors.initials: W
authors.lastname: Kempf
authors.forename: Jivko
authors.initials: J
authors.lastname: Kamarashev
authors.forename: Giulia
authors.initials: G
authors.lastname: Spallone
authors.forename: Ralph
authors.initials: R
authors.lastname: Braun
authors.forename: Thomas
authors.initials: T
authors.lastname: Wiesner
authors.forename: Lars E
authors.initials: LE
authors.lastname: French
authors.forename: Reinhard
authors.initials: R
authors.lastname: Dummer
mesh_terms: D000293:Adolescent; D002465:Cell Movement; D056915:DNA Copy Number Variations; D046169:Dermoscopy; D005260:Female; D006801:Humans; D008544:Melanocytes / Q000473:pathology*; D008545:Melanoma / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D018613:Microscopy, Confocal; D012871:Skin Diseases / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology