Congenital melanocytic nevus – What are the potential complications?

Congenital melanocytic nevi (CMN) are benign cutaneous lesions resulting from post-zygotic somatic mutations. The estimated incidence in newborns ranges from 1% to 6%. Although most cases follow a benign course, those of larger size are associated with an increased risk of severe complications, such as cutaneous melanoma, leptomeningeal melanoma, and neurocutaneous melanosis. The psychosocial impact of these often disfiguring lesions has significant repercussions on the quality of life of children and their families. The aim of the present work is to review the existing literature on the management of CMN, with particular attention to the various complications that may arise. Review articles, systematic reviews, and case series, in Portuguese and English, published since 2010, were included. The diagnosis of a CMN includes clinical examination, which may vary, dermatoscopy, and histopathology. In large nevi, dermatological and neurological monitoring is essential, with recommended regular photographic documentation and brain and spinal cord magnetic resonance imaging before 6 months of age, to screen for possible neurological anomalies in high-risk patients. The detection of alarm signs, such as rapid growth, bleeding, pain, ulceration, or development of nodules, should be immediately evaluated, preferably by a dermatologist. The therapeutic approach should be individualized and multidisciplinary, aiming to reduce the risk of melanoma and mitigate its esthetic impact.