Neurocytoma of spinal cord.

We report a case of spinal cord neurocytoma in a 67-year-old man who had experienced a progressive numbness of the left foot during the previous 4 years. Magnetic resonance imaging showed a well-defined intramedullary tumor located at the T10-T11 level. The pathological examination revealed histological characteristics described in neurocytomas. The tumor cells showed a uniform small nucleus and clear or slightly eosinophilic cytoplasm with frequent perinuclear halos, resembling the picture of oligodendroglioma. Some tumor cells exhibited mature ganglion cell appearance. Electron microscopy showed cells with microtubules and dense-core vesicles in their cytoplasm and cytoplasmic process. Immunohistochemically, the majority of tumor cells expressed synaptophysin and neuron-specific enolase. We conclude that this tumor is an exceptional case of neurocytoma located in the spinal cord, and consider that the term neurocytoma can be applied to tumors with neuronal differentiation intermediate between neuroblastoma and ganglioneuroma, even if arising in CNS outside of the intracranial ventricular system.