Rapid immunocytochemistry based on alternating current electric field using squash smear preparation of central nervous system tumors

Abstract

The role of intraoperative pathological diagnosis for central nervous system (CNS) tumors is crucial for neurosurgery when determining the surgical procedure. Especially, treatment of Carmustine (BCNU) wafers requires a conclusive diagnosis of high grade glioma (HGG) proven by intraoperative diagnosis. Recently, we demonstrated the usefulness of rapid immunohistochemistry (R-IHC) that facilitates antigen-antibody reaction under alternative current (AC) electric field in the intraoperative diagnosis of CNS tumors; however, a higher proportion of water and lipid in the brain parenchyma sometimes leads to freezing artifacts, resulting in poor quality of frozen sections. On the other hand, squash smear preparation of CNS tumors for cytology does not affect the frozen artifacts, and the importance of smear preparation is now being re-recognized as being better than that of the tissue sections. In this study, we established the rapid immunocytochemistry (R-ICC) protocol for squash smears of CNS tumors using AC electric field that takes only 22 min, and demonstrated its usefulness for semi-quantitative Ki-67/MIB-1 labeling index and CD 20 by R-ICC for intraoperative diagnosis. R-ICC by AC electric field may be a substantial tool for compensating R-IHC in inappropriate frozen sections and will be applied for broad antibodies in future.(195 words) 3

The impact of the MIB-1 index on facial nerve outcomes in vestibular schwannoma surgery

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Filter paper‐assisted cell transfer (FaCT) technique: A novel cell‐sampling technique for intraoperative diagnosis of central nervous system tumors

“…Several reports have indicated that the frozen sectioning and squash smears require a sample with a minor axis of at least 1 to 2 mm . Shah et al and Rao et al reported that cytodiagnosis using squash smears was impossible in 14.8% and 6.7% of cases, respectively, although their data may have been based on insufficient amounts of tumor tissue in some cases.…”