Giant Congenital Melanocytic Naevi in Newborns: A Case Series

Abstract

Giant Congenital Melanocytic Naevi (GCMN) is a very rare condition that mostly occurs due to an oncogenic mutation involving the NRAS (neuroblastoma RAS viral oncogene homologue) gene. GCMNs can be clinically diagnosed due to their typical features, but histopathology confirms the diagnosis. GCMN has a high propensity for transforming into malignant melanoma and leptomeningeal melanocytosis, leading to neurological deficits such as epilepsy and neurofibromatosis. As it is associated with Central Nervous System (CNS) melanosis, Magnetic Resonance Imaging (MRI) of the brain and spine is crucial. Here, three cases are reported of the babies born with GCMN from August 2022 to July 2023 in a tertiary care hospital among a total of 11,915 live births, where the incidence is much higher than found in the literature. Present series describes three cases with GCMN, including clinical features, MRI findings, short-term outcomes, risk factors, and modalities of the management. All three cases showed extensive blackish pigmented patches involving most of the body surface and MRI evidence of Neurocutaneous Melanosis (NCM). The third baby succumbed to death due to fulminant sepsis on day 2 of life. Management of GCMN requires a multimodal approach, including medical, surgical, chemotherapeutic, palliative, and psychological support for patients as well as parents, and follow-up is necessary for the early detection of malignant transformation. Detailed knowledge of this very rare condition may enable us to develop newer treatment modalities to achieve better outcomes in the near future.

Keywords

• leptomeningeal melanocytosis
• malignant melanoma
• multimodal approach
• pigmentation
• skin patch