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. Here we present a case of a 38 years old male with primary diffuse leptomeningeal melanomatosis with presence of a NRASQ61K mutation without features of neurocutaneous melanosis.
Keywords: Autopsy; Melanomatosis; Meningeal neoplasms; NRAS; Primary melanocytic tumors.