title: Nevus-associated melanomas: clinicopathologic features.
abstract: OBJECTIVE
  The clinical significance of nevus-associated melanoma compared with de novo melanomas remains controversial. It has been suggested that nevus-associated melanomas have a higher Breslow thickness and therefore worse prognosis. Over a 10-year period, this study evaluated the incidence of nevus-associated melanoma and its prognostic significance related to clinicopathologic features.
  
  
  METHODS
  Cross-sectional study from 1995 through 2004 in a dermatopathology referral center. With available data, we evaluated sex, primary location, histologic subtype, Breslow thickness, Clark level, presence of ulceration, associated lesion, and histologic subtype of the associated lesion.
  
  
  RESULTS
  Of 135,653 pathologic records from skin biopsy specimens over a 10-year period, 1,190 melanoma records were selected. Nevus-associated melanomas corresponded to 390 (32.8%) melanomas, with thin melanomas having a nevus 1.52 times the association observed with thick melanomas (>1.01 mm; 95% confidence interval, 1.16-1.99; P < .001). Superficial spreading melanoma was the most frequent, while no lentigo maligna melanoma was associated with nevi. The median Breslow thickness of nevus-associated melanomas was lower than that of de novo melanomas.
  
  
  CONCLUSIONS
  Nevus-associated melanomas, which represent one-third of the melanomas in southeast Brazil, are associated with intermittent sun exposure, superficial spreading melanomas, and lower Breslow thickness. This is one of the largest series describing nevus-associated melanomas in Latin America.
authors.affiliation: From the Department of Dermatology, Federal University of São Paulo, São Paulo, Brazil; danielleshitara@yahoo.com.br.
authors.forename: Danielle
authors.initials: D
authors.lastname: Shitara
authors.affiliation: From the Department of Dermatology, Federal University of São Paulo, São Paulo, Brazil;
authors.forename: Mauricio M
authors.initials: MM
authors.lastname: Nascimento
authors.affiliation: Melanoma Unit, Dermatology Department, Hospital Clinic of Barcelona, IDIBAPS, Universitat de Barcelona, Barcelona, Spain and CIBER de Enfermedades Raras, Instituto de Salud Carlos III, Barcelona, Spainand;
authors.forename: Susana
authors.initials: S
authors.lastname: Puig
authors.affiliation: From the Department of Dermatology, Federal University of São Paulo, São Paulo, Brazil;
authors.forename: Sérgio
authors.initials: S
authors.lastname: Yamada
authors.affiliation: From the Department of Dermatology, Federal University of São Paulo, São Paulo, Brazil; Department of Pathology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Milvia M S S
authors.initials: MM
authors.lastname: Enokihara
authors.affiliation: From the Department of Dermatology, Federal University of São Paulo, São Paulo, Brazil; Department of Pathology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Nilceo
authors.initials: N
authors.lastname: Michalany
authors.affiliation: From the Department of Dermatology, Federal University of São Paulo, São Paulo, Brazil;
authors.forename: Ediléia
authors.initials: E
authors.lastname: Bagatin
mesh_terms: D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008545:Melanoma / Q000453:epidemiology / Q000473:pathology*; D009506:Nevus / Q000453:epidemiology / Q000473:pathology*; D009508:Nevus, Pigmented / Q000453:epidemiology / Q000473:pathology; D011379:Prognosis; D012878:Skin Neoplasms / Q000453:epidemiology / Q000473:pathology*; D013472:Sunlight / Q000009:adverse effects; D000096142:Cutaneous Malignant Melanoma
keywords: Breslow; De novo melanoma; Histologic subtype; Nevus-associated melanomas