Neurocutaneous melanosis (NCMS) is a rare disorder characterized by multiple or giant congenital nevi [DS:H02874] and excessive proliferation of melanocytes in the leptomeninges and brain parenchyma. Nearly two-thirds of children with NCMS will develop neurologic symptoms including seizures, hydrocephalus, developmental delay and motor problems. Patients with NCM are at high risk of developing leptomeningeal melanoma. The prognosis for leptomeningeal melanoma is poor. It has been reported that the majority of NCMS is a result of somatic mosaicism due to a single postzygotic mutation in codon 61 of NRAS.
Category
Neoplasm
Brite
Human diseases in ICD-11 classification [BR:br08403]
02 Neoplasms
Benign neoplasms, except of lymphoid, haematopoietic, central nervous system or related tissues
Benign non-mesenchymal neoplasms
Benign cutaneous neoplasms
2F20 Benign cutaneous melanocytic neoplasms
H02875 Neurocutaneous melanosis
Kinsler VA, Thomas AC, Ishida M, Bulstrode NW, Loughlin S, Hing S, Chalker J, McKenzie K, Abu-Amero S, Slater O, Chanudet E, Palmer R, Morrogh D, Stanier P, Healy E, Sebire NJ, Moore GE
Title
Multiple congenital melanocytic nevi and neurocutaneous melanosis are caused by postzygotic mutations in codon 61 of NRAS.
