Primary melanoma of the central nervous system (CNS) was not known until 1859, when Virchow1described the first case of "diffuse melanosarcomatosis of the central nervous system." In a thorough search through the American and European literature we found only 45 cases of primary involvement of the CNS (Table 1). None of these cases had been diagnosed without surgical intervention or autopsy because there are no characteristic signs or symptoms. It seems justified, therefore, to report one more case, that of a primary intramedullary melanoma of the cord with the unique finding of metastases to the brain. The original diagnosis was acute transverse myelitis. The histogenesis of primary CNS melanoma is an interesting, as-yet-unsolved problem. Various theories have been proposed and will be discussed briefly. Report of Case The patient, a woman 50 years old, was admitted to the neurological service of Lenox Hill Hospital on May 20, 1959,