Tunlametinib for NRAS-mutated pediatric melanoma arising from a giant congenital melanocytic nevus: A rapidly progressive case

A 4.6‑year‑old boy presented with a Giant Congenital Melanocytic Naevus (GCMN), present since birth, involving the abdomen, back, waist and both thighs. At age 3, a nodule was detected within the area of the nevus on the right waist, which was histopathologically confirmed as melanoma. In the absence of any intervention, additional nodules appeared in the right inguinal and axillary regions within 5 months and progressively enlarged. Genomic testing identified NRAS exon 2 mutations (G12C/A/V and G13R/V/C, with the exact variants undetermined)，no mutations were detected in CKIT (exons 9, 11, 13, and 17), PDGFRA (exons 12 and 18), or BRAF (NM_004333.4).