Cytology of microcystic meningioma in crush preparation

Microcystic meningioma is a rare variant of meningioma, showing microcystic formations throughout the tumor. To the best of our knowledge, there have been no reports describing cytologic findings of microcystic meningioma. Ou r case was a 66-yr-old woman with a tumor mass adhered to the dura matter. The crush preparations of a smalt tissue fragment resected from the mass sh owed medium- to large-sized, well-cohesive clusters or sheets of uniform tu mor cells. The tumor cells did not show a feathering-of pattern. Various-si zed cystic spaces were observed within the clusters and sheets. The cytopla sm was relatively abundant, and the nuclear: cytoplasmic ratio was lower th an that of classic meningioma. We believe that the cystic spaces within the cell clusters or sheets are characteristic of microcystic meningioma. The cytology of microcystic meningioma seen in our case was similar to that of metastatic adenocarcinoma, but relatively monotonous bland cells, smooth nu clear outline, and inconspicuous nucleoli led us to the diagnosis of mening ioma rather than adenocarcinoma. (C) 2000 Wiley-Liss, Inc.