NRAS and primary melanoma of the central nervous system: Thus far, all primary childhood melanomas of the CNS and leptomeningeal melanocytosis were found to harbor somatic NRAS mutations: in the 6 cases reported in literature, including the present case, a codon 61 mutation in NRAS was demonstrated (1 case Q61L, 3 cases Q61R, 2 cases Q61K)[6,7,9].