Primary melanocytic tumors of central nervous system represent rare tumors arising from melanocytes of the leptomeninges. These neoplasms include focal forms like melanocytoma and primary malignant melanoma and diffuse forms like leptomeningeal melanocytosis and primary leptomeningeal melanomatosis. The clinical diagnosis remains challenging, with clinical and radiologic features overlapping with other more common diseases 1).
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Girolami I, Cima L, Ghimenton C, Zannoni M, Mombello A, Riva G, Cirielli V, Corradi G, Vogrig A, Di Stefano G, Novelli L, Gessi M, Eccher A. NRASQ61K mutated diffuse leptomeningeal melanomatosis in an adult patient with a brief review of the so-called “forme fruste” of neurocutaneous melanosis. Brain Tumor Pathol. 2018 Oct;35(4):217-223. doi: 10.1007/s10014-018-0328-x. Epub 2018 Aug 25. PMID: 30145692.