Large congenital melanocytic nevi and neurocutaneous melanocytosis: one pediatric center's experience.

BACKGROUND: Large congenital melanocytic nevi (LCMN) predispose to neurocutaneous melanocytosis (NCM), which is associated with significant morbidity and mortality.

OBJECTIVE: To identify risk factors for NCM in patients with LCMN and suggest guidelines for their management.

METHODS: Medical records of patients with LCMN were reviewed at Sainte-Justine Hospital between 1980 and 2006. Presence of multiple satellite nevi and posterior midline location were evaluated as risk factors for NCM using chi-square test. Magnetic resonance imaging scans were reviewed by a neuroradiologist.

RESULTS: Twenty-six of 52 patients underwent radiologic investigation. Six of 26 (23%) had NCM. Patients with this condition are more likely to have multiple satellite nevi (100% vs 50%, P = .03) and have a trend to posterior midline location of their LCMN (100% vs 60%, P = .08). Patients with NCM are more likely to have both multiple satellite nevi and posterior midline location (100% vs 25%, P = .002). Radiologic findings are also presented.

LIMITATIONS: This was a retrospective case series with imprecise chart data in 38% of cases.

CONCLUSION: The presence of multiple satellite nevi alone or with associated posterior midline location of LCMN is associated with a higher risk of NCM. We recommend magnetic resonance imaging testing before 4 months of age in patients with these features.