title: Pigmented lesions in children: when to worry.
abstract: OBJECTIVE
  Although the incidence of melanoma in adolescents and adults has risen dramatically in the past few decades, childhood melanoma remains uncommon. It is therefore important for pediatricians to be aware of the natural history and clinical spectrum of melanocytic nevi in children as well as potentially worrisome features of pigmented lesions.
  
  
  RESULTS
  Recent studies have provided insight into the development, evolution and molecular bases of acquired and congenital melanocytic nevi during childhood. This review summarizes the types of melanocytic nevi that are commonly observed in children, environmental (e.g. sun exposure) and genetic (e.g. the familial atypical mole and melanoma syndrome) factors that can contribute to the development of nevi and future risk of melanoma, and phenotypic markers (e.g. numerous acquired nevi or the 'red hair phenotype') that signal the need for periodic total-body cutaneous examinations. Current concepts of the risks associated with congenital melanocytic nevi of different sizes and strategies for the management of various types of nevi (including congenital, blue and Spitz nevi) are presented, and data on the clinical presentations and biologic behavior of prepubertal melanoma are discussed.
  
  
  CONCLUSIONS
  Clinical and molecular investigations have helped to better understand the characteristics of melanocytic nevi and define pathways of melanocytic tumorigenesis.
authors.affiliation: Department of Dermatology, New York University School of Medicine, New York 10016, USA. schafj04@med.nyu.edu
authors.forename: Julie V
authors.initials: JV
authors.lastname: Schaffer
mesh_terms: D002648:Child; D003937:Diagnosis, Differential; D006801:Humans; D008545:Melanoma / Q000175:diagnosis / Q000235:genetics / Q000601:surgery; D018329:Nevus, Blue / Q000175:diagnosis / Q000601:surgery; D018332:Nevus, Epithelioid and Spindle Cell / Q000175:diagnosis / Q000601:surgery; D009508:Nevus, Pigmented / Q000150:complications / Q000151:congenital / Q000175:diagnosis* / Q000235:genetics / Q000601:surgery; D012878:Skin Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000601:surgery