Rosette-forming glioneuronal tumor with dissemination throughout the ventricular system: a case report.

A 33-year-old female was found to have a rosette-forming glioneuronal tumor (RGNT) occurring within the fourth ventricle with multifocal extension to the third and lateral ventricles. She presented with headaches, blurred vision, nausea, and intermittent dizziness. A brain magnetic resonance imaging (MRI) scan showed hydrocephalus and multifocal nodules throughout the ventricular system with the largest mass occupying the fourth ventricle. An endoscopic third ventriculostomy and biopsy were performed. Histological examination demonstrated a glioneuronal neoplasm with the characteristic features of RGNT. While the histopathological features of our case are well in accord with those reported in the literature, the multifocal intraventricular growth pattern has only been described twice before. Moreover, RGNT of the fourth ventricle with dissemination throughout the supratentorial ventricles has only been described once before. Long-term studies are required to assess the best treatment modalities and clinical behavior of this extremely rare disseminated RGNT entity.