CLINICS 2011;66(3):493-499 REVIEW Atypical mole syndrome and dysplastic nevi: identification of populations at risk for developing melanoma - review article Juliana Hypo´ lito Silva,I Bianca Costa Soares de Sa´ ,II Alexandre Leon Ribeiro de A´ vila,II Gilles Landman,III Joa˜ o Pedreira Duprat NetoII I Oncology School Celestino Bourroul - Hospital AC Camargo, Sa˜ o Paulo, SP, Brazil. II Skin Oncology Department - Hospital AC Camargo - S a˜o Paulo, SP, Brazil. III Pathology Department - Hospital AC Camargo - S a˜o Paulo, SP, Brazil. Atypical Mole Syndrome is the most important phenotypic risk factor for developing cutaneous melanoma, a malignancy that accounts for about 80% of deaths from skin cancer. Because the diagnosis of melanoma at an early stage is of great prognostic relevance, the identification of Atypical Mole Syndrome carriers is essential, as well as the creation of recommended preventative measures that must be taken by these patients. KEYWORDS: Dysplastic Nevus Syndrome; dysplastic nevi; melanoma; early diagnosis; Risk Factors. Silva JH, de S a´ BC, Avila ALR, Landman G, Duprat Neto JP. Atypical mole syndrome and dysplastic nevi: identification of populations at risk for developing melanoma - review article. Clinics. 2011;66(3):493-499. Received for publication on November 23, 2010; First review completed on November 24, 2010; Accepted for publication on November 24, 2010 E-mail: bianca.sa@terra.com.br Tel.: 55 11 2189-5135 DOI:10.1590/S1807-59322011000300023 INTRODUCTION The incidence of cutaneous melanoma has increased rapidly worldwide.1-5 Although it corresponds to only 4% of all skin cancers, it accounts for 80% of skin cancer deaths.4 Because early detection of the disease is implicit in its cure and only 14% of patients with metastatic disease survive beyond 5 years,4-6 knowledge of factors that increase an individual’s risk for developing melanoma and diagnosis at an early stage of the disease have great prognostic relevance. The risk factors for developing melanoma are both genetic and environmental, especially the presence of multiple melanocytic nevi, dysplastic nevi and atypical mole syn- drome (AMS), as the main clinical phenotypic susceptibil- ity.4-9 In 1820, Norris10 described what is currently considered in a family predisposed to melanoma. In 1978, Clark11 reported an increased incidence of cutaneous melanoma in families with multiple melanocytic lesions, introducing the melanoma tumor progression model from melanocytic nevi.11,12 At the time, Clark used the term B-K mole syndrome using the initials of the patients surnames.11 Currently, the terms AMS, Dysplastic Nevus Syndrome and Familial Atypical Multiple-Mole Melanoma Syndrome (FAMMM) have been employed.12 In 1985, Elder13 extended the theory of ‘‘nevus-melanoma’’ for sporadic dysplastic nevi as a possible precursor to sporadic melanoma. Copyright 2011 CLINICS – This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non- commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 493 Several studies have shown that the presence of dysplas- tic nevi considerably increases the risk of developing melanoma, which demonstrates that these lesions, aside from being precursors to disease are also important risk markers.4,7,14-19 Nevertheless, the risk magnitude varies among patients with this type of pigmented lesion.3,4,15,16,20 There are still controversies in the literature regarding the nomenclature, clinical definition, dermoscopic characteris- tics and histopathological, genetic and molecular patterns of dysplastic nevi.4,8 In this literature review of dysplastic nevi and AMS, we demonstrate the importance of a complete dermatological examination for the evaluation and monitoring of patients with dysplastic nevi and AMS and suggest criteria for follow-up. Epidemiology Dysplastic nevi are relatively common in the general population.8 Reports have described the prevalence ranging from 2% to 53% in different studies, depending on the diagnostic criteria (clinical or histological).8 A more accurate estimate is considered to be about 2%-8% of Caucasians, with a predilection for young individuals (less than 30 to 40 years of age).18 The frequency of dysplastic nevi in patients with a history of melanoma is much higher: 34% to 59%.18 Evidence suggests that sun exposure, in addition to genetic susceptibility, may increase the appearance of such nevi.1,8,18 Data concerning the prevalence of AMS are difficult to document in part due to the large variability in the diagnostic criteria employed by different studies. Based on estimates by the National Institutes of Health (NIH), it has been estimated that about 32,000 individuals were carriers