Large congenital melanocytic nevi: therapeutic management and melanoma risk: a systematic review

Large congenital melanocytic nevi (LCMN) are defined as congenital melanocytic nevi having a projected adult size exceeding 20 cm in diameter. They occur in 1 in 20,000 to 1 in 500,000 newborns. Therapeutic management of LCMN remains controversial and is often decided according to melanoma risk.

We sought to synthesize all data available on LCMN-associated melanoma risk, therapeutic assessment, and psychosocial and aesthetic impacts.

A MEDLINE search was conducted (1966-February 2011), and 22 French- and English-language databases were consulted. Case reports and reviews were excluded, as were studies with fewer than 20 patients and insufficient information about the nevi. Studies were qualitatively assessed and analyzed according to predefined criteria.

Fourteen studies were selected (956 references). A total of 52 (2%) melanomas (2 in 1 patient) developed in 2578 patients. Age at diagnosis ranged from birth to 58 (mean 12.6) years. Primary melanomas were mostly cutaneous (82%) and 68% were located on the trunk; 7 melanomas were visceral. Melanoma-associated LCMN size exceeded 40 cm for 74% and 94% had satellite nevi. Of melanomas, 55% were fatal, with age at death ranging from 0.9 to 40 (mean 10) years. Eighteen patients were still alive with a mean follow-up of 10.2 years. Melanoma incidence assessable for 216 cases was estimated at 2.3 per 1000 patient-years. Behavioral/emotional problems independent of the lesion were common in children.

Selected studies were heterogeneous.

LCMN management should be individualized with respect to melanoma risk, and aesthetic and psychosocial aspects.