Intraoperative cytology of central neurocytoma mimicking oligodendroglioma

Central neurocytomas (CNs) are uncommon tumors of the central nervous system. These tumors have a predilection for the lateral ventricles of young adults and are known to display characteristic neuroimaging and histomorphologic features. Typically, CNs are associated with a favorable outcome, although cases with more aggressive clinical course with recurrences are not unknown. Most descriptions of this tumor are available in the form of isolated histopathology-based case reports and small series. Cytology-based publications of CN are rare. Here, we report a case of CN in a 22-year-old girl. Intra-operative squash cytology and subsequent histopathology of the tumor simulated an oligodendroglioma and a clear cell ependydoma. Final confirmation was obtained on immunohistochemistry. This paper discusses the salient cytological, histomorphological and immunohistochemical features of CN that are useful in distinguishing from its mimickers.