Core concepts in congenital melanocytic nevi and infantile hemangiomas

Congenital melanocytic nevi (CMN) and infantile hemangiomas are commonly encountered in newborns and may present diagnostic and therapeutic dilemmas for medical practitioners. Herein, we review and discuss these two important clinical entities and focus on core issues and recent advances.

Melanoma risk for patients with CMN is greatest in infants with large CMN located on the trunk, CMN greater than 40 cm, and multiple satellite nevi. Recent histological and molecular findings have been described to assist in differentiating benign proliferative nodules arising in CMN from melanoma. Multiple CMN and associated neurological lesions have recently been shown to be due to a single postzygotic mutation in NRAS [neuroblastoma RAS viral (v-ras) oncogene homolog]. Over the last several years, numerous advancements have occurred in redefining the clinical course of infantile hemangiomas, describing clinical syndromes associated with infantile hemangiomas and treating complicated infantile hemangiomas. The nonselective β-blocker propranolol has become first-line therapy for the treatment of complicated infantile hemangiomas. Topical timolol shows promise for the treatment of certain types of infantile hemangiomas.

Although most CMN and infantile hemangiomas do not require active intervention, understanding which lesions may impact the overall health of the infant assists in early intervention. This article touches on core concepts in the clinical evaluation and treatment of CMN and infantile hemangioma.