Specific Imaging Findings

Central neurocytomas are typically located in the frontal horn and corpus of the lateral ventricles. They are isodense to brain on CT and contain multiple cysts, generally small ones. Up to two-thirds of them contain calcifications and nearly all show some contrast enhancement. Intraventricular blood is not uncommon. On MR imaging, T1 and T2 sequences typically demonstrate heterogeneous signal intensity with cysts, hemorrhage and large flowvoids. Central neurocytomas are hyperintense on FLAIR images and commonly show reduced diffusion on ADC maps. Associated hydrocephalus is very frequent. Perfusion studies show increased relative cerebral blood volume of the tumor. MR spectroscopy shows high choline and low n-acetyl aspartate, while the presence of a high glycine peak (at 3.55 ppm) appears to be a characteristic feature. Rare extraventricular neurocytomas arise in frontal and parietal lobes and exhibit the same imaging features – intratumoral cysts, calcifications and/or blood products.

Pertinent Clinical Information

Although central neurocytoma may occur at any age and equally in both genders, it tends to be found in younger individuals (20–40 years of age). They may be incidentally discovered or produce signs of increased intracranial pressure or intraventricular (with extension into the subarachnoid spaces) hemorrhage. Large tumors may compress the hypothalamus and produce hormonal and visual changes. As it is a localized tumor, complete resection is frequently curative and survival rates even after incomplete resection are over 80% at 5 years.