Define neurocytoma: Neurocytoma represents an uncommon neuronal tumor that develops within the central nervous system, most frequently along the lateral ventricles near the foramen of Monro, and less commonly in the brain parenchyma as extraventricular neurocytoma (EVN).
Most of these tumors correspond to WHO Grade 2, with a generally favorable course, but atypical neurocytomas may recur and require closer monitoring.
Pathology and Classification
1. Histopathologic Features
Composed of small, uniform neuronal cells embedded in a fine neuropil background.
Synaptophysin-positive, confirming neuronal origin.
Ki-67/MIB-1 labeling index >2–4% indicates atypical neurocytoma with higher recurrence potential.
2. WHO 2021 Classification
Neurocytoma Central (Grade 2) – intraventricular, usually benign
Extraventricular neurocytoma (Grade 2) – parenchymal, may show slightly more variable biological behavior
Clinical Presentation
1.Central Neurocytoma
Symptoms arise mainly from CSF obstruction and hydrocephalus:
Positional headache
Nausea, vomiting, or papilledema
Cognitive impairment or memory issues
Seizures in some cases
2.Extraventricular Neurocytoma
Seizures (especially cortical involvement)
Focal neurological deficits such as weakness or sensory loss
Behavioral or cognitive changes
Diagnosis
1. Radiological Examination
Neurocytoma radiology: MRI is the gold standard, showing a heterogeneous mass with cystic or calcified components
CT may better identify calcifications
Central neurocytoma radiology findings may mimic oligodendroglioma or ependymoma, so histology is mandatory
2. Histopathology
Tissue sampling confirms diagnosis
Synaptophysin positivity and Ki-67 index guide prognosis
Treatment Options
1. Microsurgical Resection
Gross total resection is the cornerstone of therapy and offers the best long-term control.
Subtotal resection carries a higher risk of recurrence.
2. Radiotherapy
Reserved for residual tumors, recurrence, or atypical histology
Can be stereotactic or fractionated depending on tumor size and location.
3. Chemotherapy
No standard role; mainly considered for refractory cases or clinical trials