Introduction: Central neurocytoma (CN) is a very rare neuronal neoplasm. The clinical implications of the potential prognostic factors for these lesions, including tumor atypia, have therefore not been clarified.
Methods: Forty CN patients were enrolled and reclassified as typical or atypical in accordance with an MIB-1 labeling index (LI) of above and below 2%.
Results: We classified our retrospective study cohort as 21 (52.5%) typical and 19 (47.5%) atypical CN cases. No significant differences were found in terms of sex, mean age, mean tumor size or tumor location between these groups. Recurrences occurred in 2 (9.5%) typical and 6 (33.3%) atypical cases. The typical CN 2-,3- and 5-year PFS rates were 100%, 100%, 92.3%, and those for the atypical group were 93.8%, 78.1%, 65.1%, respectively (p = 0.02). The PFS rates did not statistically differ by treatment modality (gross total resection alone, subtotal resection (STR) alone and STR plus radiation therapy (RT) or radiosurgery (RS)) either in the whole cohort (p = 0.75) or in the typical CN and atypical CN subgroups (p = 0.45 and 0.98, respectively). An atypical histology was the only prognostic indicator of recurrence by univariate analysis (hazard ratio: 5.40, p = 0.04).
Conclusions: An atypical lesion (MIB-LI > 2%) is an important prognostic indicator in CN. The clinical implications of the extent of resection for CN patients are still debatable. The use of STR plus RT or RS may be a viable treatment strategy for CN but different therapeutic and follow-up approaches for atypical CN will be needed.
Keywords: Atypical; Central neurocytoma; Prognosis; Treatment.