Cytopathology of neoplasms of the central nervous system in specimens obtained by the Cavitron Ultrasonic Surgical Aspirator.

The Cavitron Ultrasonic Surgical Aspirator (CUSA) is a dissecting system that removes tissue by vibration, irrigation and suction; fluid and particulate matter from tumors are aspirated and subsquently deposited in a canister. The CUSA permits the neurosurgeon to remove large tumors by debulking them quickly and effectively, without traction or manipulation and with minimal transmission of movement to adjacent normal tissues. The cytomorphologic appearances of 22 central nervous system tumors in CUSA samples were evaluated and compared with the findings in biopsy or resection specimens. Papanicolaou-stained and Diff-Quik-stained Cytospin preparations were prepared from the saline irrigation fluid along with a cell block in every case. Three specimens (13.6%) were insufficient for interpretation. Of the materials from seven astrocytic neoplasms examined, two were insufficient for diagnosis. The other insufficient case was tissue obtained from an ependymoma. All 11 meningiomas had diagnostic material in the slides and cell blocks. In general, the cytologic smears and cell block preparations were best preserved in meningiomas and schwannomas. Varying degrees of degeneration were noted in the glial neoplasms. Since tissue obtained from the CUSA may represent the bulk of the specimen, the examination of cytologic smears and especially cell blocks from the tissue that "went down the sucker" and were previously discarded may be quite useful.