|Sagittal T1W MR||Axial T2W MR|
WHO Grade I
Cell of Origin: Neurons
Common Locations: Intraventricular (Lat >> 3rd) (often attached to septum pellucidum)
Demographics: Young adults (mean age: 25-30)
Clinical Presentation: Nausea, vomiting, headache due to obstructive hydrocephalus.
Histology: Uniform appearance of small, round cells mimics oligodendroglioma. Electron microscopy may demonstrate neuronal features.
Special Stains: Purely neuronal origin demonstrated by neuronal markers (synaptophysin, neuronal specific enolase) and negativity to glial markers.
Progression: Slow-growing, benign tumor; no extraventricular extension. Resection usually curative.
Radiology: Well-circumscribed, lobulated intraventricular mass. Often (50%) with bulky calcifications, best demonstrated on CT. Isodense/slightly hyderdense on CT. May be isointense to gray matter on both T1 and T2-weighted MR images. MR often demonstrates small "cysts".
Comments: Previously misdiagnosed as intraventricular oligodendroglioma. Rare reports of extraventricular (parenchymal) location. Rarely, spontaneous intraventricular hemorrhage.