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Neurocutaneous melanocytosis (NCM) is a rare congenital syndrome presenting as congenital melanocytic naevus (CMN) and melanocytosis with infiltration of brain parenchyma and/or leptomeninges.1 About 20% of patients with giant CMN will have NCM. The prevalence of NCM is 1 in 50 000 to 1 in 200 000 people and symptomatic in a third to half.