Extraventricular Neurocytoma of the Sellar Region：A Case Report

Abstract

Extraventricular neurocytoma（EVN）is a rare neuronal neoplasm that originates outside the ventricle. We report the case of a 27‒year‒old woman with an EVN involving the sellar region. The patient had irregular menstruation and visited our hospital for evaluation. Brain magnetic resonance imaging（MRI） revealed a solid sellar mass. She underwent endoscopic endonasal transsphenoidal surgery（eTSS）, and the tumor was partially resected. Histopathological evaluation showed a glial tumor. Follow‒up MRI performed 18 months later revealed enlargement of the residual lesion. The patient underwent repeat eTSS for subtotal resection of the lesion. Histopathological findings showed oligodendroglia‒like cells, and immunohistochemical analysis showed cells that were immunopositive for synaptophysin and neuronal nuclei and immunonegative for glial fibrillary acidic protein and isocitrate dehydrogenase 1 R132H. The patient was definitively diagnosed with EVN. She underwent Gamma knife radiosurgery postoperatively with reduction in the size of the residual lesion.