Intraventricular neurocytoma with massive brain stem involvement in a 5-year-old child.

INTRODUCTION: Central neurocytoma is a tumor of neuronal origin that should be taken into consideration in the differential diagnosis of intraventricular neoplasms. Reports of neurocytomas with an extraventricular localization are rare: to our knowledge, the case described here is the first in which a neurocytoma developed within the ventricles but also invaded the brain stem. CASE REPORT: The authors describe the unusual case of a 5-year-old boy with an intraventricular neurocytoma presenting with massive involvement of the basal nuclei and the brain stem. The patient underwent first biopsy and then surgery for ventricular-peritoneal shunting and partial removal of the tumor. Histology showed the tumor to be a typical neurocytoma with Mib-1 <2%. The postoperative course was uneventful. At 3 years' follow-up, the patient's clinical condition is stable and there are no signs of disease progression. DISCUSSION: The literature is reviewed and the characteristics of this unusual tumor are discussed.