Related Experiment Video
Updated: Mar 8, 2026
Author Spotlight: Anterior HR-OCT as a Non-Invasive Tool for Characterizing Ocular Surface Squamous Neoplasia
Published on: August 9, 2024
Congenital Melanocytic Nevus Syndrome: A Case Series
A Recio1, A I Sánchez-Moya2, V Félix3
1Unidad de Neonatología, Servicio de Pediatría, Complejo Hospitalario de Toledo, Toledo, España.
Abstract:
Congenital melanocytic nevus syndrome (CMNS) is the result of an abnormal proliferation of melanocytes in the skin and central nervous system caused by progenitor-cell mutations during embryonic development. Mutations in the NRAS gene have been detected in many of these cells. We present 5 cases of giant congenital melanocytic nevus, 3 of them associated with CMNS; NRAS gene mutation was studied in these 3 patients. Until a few years ago, surgery was the treatment of choice, but the results have proved unsatisfactory because aggressive interventions do not improve cosmetic appearance and only minimally reduce the risk of malignant change. In 2013, trametinib was approved for use in advanced melanoma associated with NRAS mutations. This drug, which acts on the intracellular RAS/RAF/MEK/pERK/MAPK cascade, could be useful in pediatric patients with CMNS. A better understanding of this disease will facilitate the development of new strategies.
Insights
Congenital melanocytic nevus syndrome (CMNS) involves abnormal melanocyte growth due to NRAS gene mutations. Trametinib, targeting the MAPK pathway, shows potential for treating pediatric CMNS, offering new therapeutic avenues.
Area of Science:
- Genetics
- Dermatology
- Pediatrics
Background:
- Congenital melanocytic nevus syndrome (CMNS) arises from embryonic progenitor-cell mutations, often involving the NRAS gene.
- Giant congenital melanocytic nevi are a significant manifestation of CMNS, impacting skin and potentially the central nervous system.
Observation:
- This study examined 5 cases of giant congenital melanocytic nevus, with 3 diagnosed with CMNS.
- NRAS gene mutations were investigated in the CMNS-affected patients.
Findings:
- Traditional surgical interventions for CMNS yield unsatisfactory cosmetic and oncological outcomes.
- Trametinib, a targeted therapy approved for NRAS-mutated melanoma, acts on the RAS/RAF/MEK/pERK/MAPK pathway.
Implications:
- Trametinib presents a promising therapeutic option for pediatric CMNS patients with NRAS mutations.
- Further understanding of CMNS pathogenesis is crucial for developing novel treatment strategies.
Related Concept Videos
01:30Skin Cancer
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
01:14Changes in Skin Color: Clinical Perspectives
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
01:20The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...