RARE-03. CHARACTERISTICS OF PATIENTS WITH NEUROCUTANEOUS MELANOSIS: THE MSK EXPERIENCE FROM 2003–2018. (5th November 2018)

• Record Type: Journal Article
• Authors: Ennin, Elsie; De Braganca, Kevin; Haque, Sofia; Marghoob, Ashfaq; Khakoo, Yasmin
• Is Part Of: Neuro-oncology. Volume 20(2018)Supplement 6
• Page Start: vi236
• Page End: vi237
• Publication Date: 2018-11-05
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noy148.981
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: BACKGROUND: The incidence of large congenital melanocytic nevi (LCMN) is 1/20, 000 with 25% of children diagnosed with neurocutaneous melanocytosis (NCM), characterized by excessive proliferation of melanocytes in the leptomeninges and brain parenchyma. Specifically the disorder represents abnormal migration of melanocyte precursors due to abnormal melanin-producing genes in primitive leptomeningeal cells. While NCM can transform to melanoma, the molecular drivers involved in NCM related melanoma are different from the drivers in patients with non-NCM related melanoma. Children who become symptomatic from NCM may have a poor prognosis overall with 25–60% developing melanoma. While melanoma typically harbors mutations in the BRAF gene, NCM has a distinct molecular signature comprised primarily of mutations in the NRAS gene. METHODS: We reviewed our institutional database from 2003–2018 and identified 47 patients with large congenital melanocytic nevi (LCMN) and NCM. Fifteen were female and 16/47 died. Five had molecular testing which revealed an NRAS mutation in the affected tissues. Four patients who developed melanoma, received targeted therapy including off label trametinib, nivolumab and/or ipilumumab. While none of these patient were longterm survivors, one patient lived for 12 months after receiving radiation therapy, nivolumab and ipilumumab. One patient with a VP shunt developed intraperitoneal melanoma, malignant ascites and subsequently died. CONCLUSIONS: While NCM which transforms to melanoma is typically fatal, new targeted therapies may offer prolonged survival. Further efforts to identify which patients are high risk are needed in an attempt to offer earlier treatment.