Melanocytic Tumors in Central Nervous System

Melanocytic tumours in the central nervous system encompass a spectrum of rare lesions arising from melanocytes within the leptomeninges and parenchyma. These range from benign meningeal melanocytomas to malignant primary melanomas and diffuse leptomeningeal melanomatosis. Clinical manifestations often include headache, seizures and focal neurological deficits, mirroring other intracranial masses. Radiological hallmarks on MRI include hyperintensity on T1-weighted sequences and variable signal on T2-weighted images, reflecting melanin content. Histopathological examination and immunohistochemistry for melanocytic markers are essential to distinguish primary lesions from metastatic melanoma. Recent molecular profiling has uncovered recurrent mutations in GNAQ, GNA11, SF3B1 and BAP1 in circumscribed tumours and NRAS and BRAF alterations in diffuse forms, offering potential therapeutic targets. Surgical resection remains the mainstay for circumscribed lesions, while diffuse disease often necessitates palliative radiotherapy and emerging systemic approaches, such as MEK inhibitors and immune checkpoint blockade. Advances in imaging, molecular diagnostics and targeted therapies are reshaping the understanding and management of these ultra-rare entities, with registries and multicentre collaborations driving progress.

Research from Nature Portfolio

Recent studies have refined the molecular taxonomy of central nervous system melanocytic tumours through high-resolution genomics and single-cell transcriptomics. These efforts delineate distinct subtypes characterised by GNAQ and GNA11 driver mutations and elucidate the tumour microenvironment, revealing immunosuppressive niches that may respond to checkpoint blockade. Preclinical models using MEK inhibitors demonstrate selective activity against GNAQ-mutant cells, supporting early-phase trials. Parallel developments in advanced imaging protocols, combining ultra-high-field MRI and novel PET tracers, show promise in differentiating melanocytoma from metastatic melanoma non-invasively. These integrated approaches are informing personalised treatment strategies and guiding the design of biomarker-driven clinical studies.

Melanocytic Tumors in Central Nervous System publication trend

The graph below shows the total number of articles in melanocytic tumors in central nervous system across all publications each year (not limited to Nature Index journals).

Technical terms

Leptomeningeal melanocytoma: A benign melanocytic neoplasm arising in the arachnoid and pia mater.

Melanomatosis: Diffuse infiltration of the leptomeninges by malignant melanocytes.

GNAQ/GNA11: Genes encoding G-protein alpha subunits frequently mutated in melanocytic tumours.

MEK inhibitor: A targeted agent that blocks the MAPK pathway downstream of RAS/RAF mutations.

Immune checkpoint blockade: Therapy that releases inhibitory signals on T cells to enhance anti-tumour immunity.

Single-cell transcriptomics: A method to profile gene expression in individual cells, revealing cellular diversity.

Hyperintensity on T1-weighted MRI: Radiological feature indicating melanin or haemorrhage within a lesion.

References

1. Primary Meningeal Melanocytic Tumors of the Central Nervous System: A Review from the Ultra-Rare Brain Tumors Task Force of the European Network for Rare Cancers (EURACAN). Cancers (2024).
2. Primary Diffuse Leptomeningeal Melanomatosis in a Child with Extracranial Metastasis: Case Report. Current Oncology (2024).
3. Primary cerebral malignant melanoma. Medicine (2017).