Nevi in children: a practical approach to evaluation

Update on melanocytic nevi in children

A new or changing melanocytic nevus in a child or adolescent often leads to concern in parents and physicians. To avoid undue alarm and unnecessary procedures, dermatologists should be aware of the natural history and clinical spectrum of nevi in pediatric patients, as well as findings that are potentially worrisome in this age group. This review provides an update on melanocytic nevi in children, focusing on their dynamic evolution over time, molecular insights into nevogenesis, and phenotypic markers for increased risk of melanoma in adolescence and adulthood. Special considerations for Spitz nevi and nevi located in particular sites (eg, scalp, acral, genital) are highlighted. Current understanding of the risks associated with congenital melanocytic nevi of different sizes and strategies for the management of children with numerous acquired nevi, Spitz nevi, and congenital nevi are also discussed.

Congenital melanocytic nevi: where are we now? Part I. Clinical presentation, epidemiology, pathogenesis, histology, malignant transformation, and neurocutaneous melanosis

Congenital melanocytic nevi (CMN) are present at birth or arise during the first few weeks of life. They are quite common, may have a heritable component, and can present with marked differences in size, shape, color, and location. Histologic and dermatoscopic findings may help suggest the diagnosis, but they are not entirely specific. CMN are categorized based on size, and larger lesions can have a significant psychosocial impact and other complications. They are associated with a variety of dermatologic lesions, ranging from benign to malignant. The risk of malignant transformation varies, with larger CMN carrying a significantly higher risk of malignant melanoma (MM), although with an absolute risk that is lower than is commonly believed. They may also be associated with neuromelanosis, which may be of greater concern than cutaneous MM. The information presented herein aims to help dermatologists determine when it is prudent to obtain a biopsy specimen or excise these lesions, to obtain radiographic imaging, and to involve other specialists (eg, psychiatrists and neurologists) in the patient's care.

Pigmented lesions in children: when to worry

PURPOSE OF REVIEW

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.

RECENT FINDINGS

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.

SUMMARY

Clinical and molecular investigations have helped to better understand the characteristics of melanocytic nevi and define pathways of melanocytic tumorigenesis.