Cytodiagnosis of Central neurocytoma in intraoperative preparations

OBJECTIVE: To assess the cytologic features in smear preparations of 3 central neurocytomas. STUDY DESIGN: Three patients with central neurocytoma underwent intraoperative frozen section diagnoses, and the cytologic evaluations are presented. RESULTS: The smears typically showed cellular tumors composed of isomorphous, round cells. The tumor cells showed ill-defined cytoplasm, oval nuclei with finely granular chromatin and micronucleoli. A fibrillary matrix in the background was noted in all cases. The tumor in the 20-year-old patient exhibited numerous giant cells with phyagocytosed hemosiderin granules between small, round tumor cells. Permanent sections, immunohistochemistry and electron microscopy confirmed that all cases were central neurocytomas. CONCLUSION: Central neurocytomas can be diagnosed reliably using combined cytologic preparations and frozen sections. The appearance of numerous macrophages that phagocytose hemosiderin between neoplastic cells should also be considered characteristic of the cytomorphology of central neurocytomas.