CENTRAL NEUROCYTOMA.

Spectroscopy was done that revealed a mild reduction in NAA throughout the tumor with increased choline to creatinine ratio.

Central neurocytoma was first described by Hassoun et al., in 1982. It is a rare tumor of the central nervous system with neurocytic differentiation and favorable prognosis. In the four-tier World Health Organization (WHO) Classification of Tumors of the Nervous System, it corresponds to a grade II/IV tumor. Central neurocytoma comprises only 0.25-0.5% of all intracranial tumors.

They occur predominantly in the third and fourth decades but can be seen in other age group

About three-quarter of the cases occur in the lateral ventricles with the foramina of Monro as the most common sites, the remaining one-quarter of the cases occur in the third ventricles. Rarely, they can occur in the cerebral hemispheres.

Their ventricular location makes symptoms and signs of hydrocephalus the most common manifestations.

RADIOLOGY-The MRI images of central neurocytoma are usually characteristic. Most of them occur as an exophytic, well circumscribed, globular mass that protrudes into the ventricles. Large tumors are not uncommon. Calcifications are common and easily identified by CT scans. Central neurocytoma that arise in the lateral ventricles typically adhere to the septum pellucidum. Hydrocephalus is common. On T2-weighted image, they are isointense to gray matter. Contrast enhancement is common but variable and it can be intense. From the imaging point of view, the differential diagnoses include heterotopia, oligodendroglioma, ependymoma, Subependymoma, subependymal giant cell astrocytoma, choroids plexus papilloma, and intraventricular meningioma,DNET.