CT and MR of meningeal melanocytoma.

The majority of melanotic neoplasms of the CNS are metastatic in origin. Rarely, a primary CNS melanoma arises from the leptomeninges, which in certain regions normally contain melanocytic cells [1]. These primary neoplasms are usually histologically and clinically malignant [2]. The meningeal melanocytoma is at the benign end of the spectrum of primary melanotic neoplasms and is less common than its malignant counterparts [2]. In this article we describe a patient with a meningeal melanocytoma adjacent to the foramen magnum. We report clinical, surgical, CT, and MR findings, as well as the pathologic features revealed by immunohistochemistry and electron microscopy.