Extraventricular neurocytoma, a comprehensive review

Extra ventricular neurocytoms (EVN) are a rare parenchymal brain tumour distinct from central neurocytomas. This review attempts to analyze a series of seven cases of EVN from a single institute against the background of available literature. Retrospective analysis of the clinical manifestation, pathological features, imaging findings, microsurgical treatment effectiveness and progression free survival of seven cases of EVN operated between 2000-2012. The study group included five females and two males in the age group 7-65 years (mean 30.71 yrs). The distribution of the lesion was as follows Lobar 4, Cerebellum 1, Pineal 1, spinal 1. The duration of clinical symptoms ranged from three months to seven years and the presentation was site and size specific. Cystic Changes (71 %), perilesional oedema (57 %) and heterogeneous contrast enhancement (85.7 %), and calcification (42 %) were a few distinct imaging characteristics. Increased perfusion correlated with atypical histology in two patients. Surgical resection remains the main management strategy for longer outcome and patients with STR + RT and GTR had comparable follow-up. Extremes of age and atypical histological features were adverse prognostic factors. EVN are rare tumors with either glial or neuronal differentiation or a potential for atypical changes. Both, GTR and STR combined with RT, offer reasonably good outcome with overall comparable survival. The available literature of EVN is limited, larger series with long term follow-ups are needed to dictate the management protocol. The role of adjuvant therapy is still debatable and needs further validation.