Central Neurocytoma & Extraventricular Neurocytoma
Central Neurocytoma
- Low-grade (G2) tumor that typically lies anteriorly within the lateral ventricle, attached to the intraventricular septum.
- Typically present in patients in their 30's and 40's and can cause obstructive hydrocephalus from pressure on the foramen of Monro.
- Most commonly develops in the lateral ventricles and 3rd ventricle and thus can block-off the foramen of Monro.
- On MRI, they are isointense on T1, hyperintense on T2, and typically will contrast enhance.
- Extraventricular neurocytoma: rarely, neurocytoma grows from the brain parenchyma, itself.
Pathology/Immunochemistry
- Oligodendroglioma-like appearance: small uniform cells with round nuclei and scant cytoplasm (gives a similar to perinuclear halos, "fried-egg cells").
- Homer Wright rosettes are possible.
- Synaptophysin (a key neuronal marker) displays prominent reactivity.
- Immunochemistry demonstrates neuronal-positivity but NOT glial markers: + for synaptophysin but NOT glial fibrillary acidic protein (GFAP).
References
- Adesina, Adekunle M., Tarik Tihan, Christine E. Fuller, and Tina Young Poussaint. Atlas of Pediatric Brain Tumors. Springer, 2016.
- Gray, Frangoise, Charles Duyckaerts, and Umberto De Girolami. Escourolle and Poirier’s Manual of Basic Neuropathology. OUP USA, 2013.
- Tonn, Jörg-Christian, Manfred Westphal, and J. T. Rutka. Oncology of CNS Tumors. Springer Science & Business Media, 2010.
- Yachnis, Anthony T., and Marie L. Rivera-Zengotita. Neuropathology E-Book: A Volume in the High Yield Pathology Series. Elsevier Health Sciences, 2012.