MELANOCYTIC NEVI, DYSPLASTIC NEVI, AND MALIGNANT-MELANOMA IN CHILDRENFROM MELANOMA-PRONE FAMILIES

Background: Melanocytic nevi, particularly dysplastic nevi (DN), are i mportant markers of increased risk of malignant melanoma in adults, bu t little is known about their prevalence and relation to melanoma in c hildren. Objective: Our purpose was to define the prevalence of DN, nu mber of nevi, and their relation to the risk of melanoma in children y ounger than 20 years of age from melanoma-prone families. Methods: One hundred twenty-five persons younger than 20 years of age, from 23 mel anoma-prone families, underwent clinical evaluation with nevus counts, photography, and biopsy of suspected melanocytic lesions and were obs erved for development of DN and melanoma. Results: In melanoma-prone f amilies, 37% of children had DN. The patients were divided into four c ategories: those with melanoma, DN (without melanoma), indeterminant ( largely because of age at examination), and unaffected. The risk of me lanoma was assessed by news number and presence of DN. High nevus numb er was strongly correlated with the presence of DN. The risk of the de velopment of melanoma in children from melanoma-prone families appeare d most related to the presence of DN (relative risk, 45; 95% confidenc e intervals, 2.6-786.4) and started at an early age. Of note, all chil dren in whom melanoma developed had DN. Conclusion: Family history of melanoma and the presence of DN defines children with a high risk for melanoma developing at an early age.