Melanocytic tumor with GNA11 p.Q209L mutation mimicking a foramen magnum meningioma

Abstract

Melanocytic tumors of the central nervous system arise from elanocytes normally found in the leptomeninges. They most comonly present as intradural-extramedullary lesions of the posterior ossa and cervical spine, but may occur throughout the neuraxis 1]. This group includes diffuse leptomeningeal melanocytosis and ocal tumors ranging from benign melanocytomas to malignant rimary CNS melanomas. Few tumors of intermediate grade (“atypcal” melanocytic tumors) have been reported [1]. Here we report n unusual intermediate-grade melanocytic tumor arising from he dura of the craniocervical junction. Its radiographic and gross ppearance were suggestive of a foramen magnum meningioma. Our ability to grade and treat CNS melanocytic tumors is limted by our poor understanding of their molecular derangements. here is some evidence that their pathogenesis resembles that of ther melanocytic neoplasms. In particular, uveal melanomas have een found to harbor frequent mutations of GNAQ [2] and GNA11 3], which encode components of two related G proteins. A recent