Hydrocephalus Secondary to Intradural Extramedullary Malignant Melanoma of Spinal Cord.

Background: Hydrocephalus secondary to spinal cord tumors is rare.

Case Description: We present a 39-year-old male with gradual-onset headache whose initial diagnosis was cerebral aneurysm and communicating hydrocephalus. The correct diagnosis was primary intradural extramedullary malignant melanoma of the spinal cord. Initial brain magnetic resonance imaging demonstrated slight dilation of cerebral ventricles and a 3-mm unruptured anterior communicating artery aneurysm. He was placed under observation therapy. Two months later he was seen again due to severe headache. There was no intracranial hemorrhage on brain computed tomography scans. As we suspected rupture of the aneurysm, we operated on him for surgical clipping; however, there was no aneurysmal rupture. We found no lesions responsible for hydrocephalus, so we placed a ventriculoperitoneal shunt. His headache subsequently resolved. Nine months later he developed gait disturbance; a large volume of ascites was observed. Gadolinium-enhanced lumbar magnetic resonance imaging revealed an intradural extramedullary mass at the L-1 to S-5 level. Cytology and immunohistochemistry of the cerebrospinal fluid and ascites identified a few atypical cells positive for HMB-45, S-100 protein, and Melan-A. Whole-body examinations detected no primary lesions outside the central nervous system. Our final diagnosis was primary intradural extramedullary malignant melanoma of the spinal cord with cerebrospinal fluid dissemination.

Conclusions: Our findings indicate that communicating hydrocephalus may be due to primary malignant melanoma of the spinal cord.