Progressive cranial polyneuropathy caused by primary central nervous system melanoma

Primary malignant melanoma of the central nervous system (CNS) is exceedingly rare. The earliest description by Virchow in 1859 has been followed by approximately 50 autopsy-proven cases reported in the literature. These tumors are considered to arise from leptomeningeal melanocytes whose embryonic origin is neural crest tissue. Given the rarity of primary CNS melanoma, the diagnosis requires a thorough search to exclude a dermatologic, ocular, or visceral site of tumor origin. We report an unusual case of primary CNS melanoma in a patient with painful, progressive cranial polyneuropathy that eluded antemortem diagnosis despite extensive clinical, radiographical, and laboratory investigations.