Cytologic features of meningiomas on crush preparations: a review.

Meningiomas are rarely subjected to aspiration, however, since they may occur outside the central nervous system, it is important to recognize their cytologic features. The goal of this study was to examine the cytologic features of meningiomas in crush preparations and cytologic imprints prepared at the time of frozen section. A total of 97 cases of meningiomas evaluated intraoperatively by frozen section with concomitant crush preparation and cytologic imprint were reviewed to assess their cytologic features. The cytologic features of meningiomas identified in our study are cohesive syncitial clusters of cells with ill-defined boundaries. The nuclei are oval and may be eccentrically placed, along with small central nucleoli. The cytologic features may not reflect the histologic subtype. The psammomatous variant can however be easily recognized in touch preps/imprints. The presence of nuclear anaplasia, macronucleoli, mitotic activity, and sheet-like growth may suggest an atypical meningioma. In conclusion, the cytologic features identified would be helpful in diagnosis of meningiomas, especially in unusual locations.