Intraoperative immunocytochemistry of cytologic scrape specimens: A rapid immunoperoxidase method for triage and diagnosis

We investigated a rapid immunoperoxidase (IPX) method utilizing a wide variety of antibodies for use on cytologic scrapings of fresh tissue that were submitted for intraoperative frozen section. The handling, fixation and IPX staining of these cytologic scrape specimens are more rapid and convenient than frozen tissue sections and spare tissues that may be of small quantity for appropriate special diagnostic studies (flow cytometry, cell markers, genetic studies, electron microscopy, and so forth). Fresh tissues from normal organs and tumors were scraped with a scalpel blade, smeared on an uncoated glass slide and immersed in 95% alcohol for one minute. Antibodies investigated by this method included: CAM 5.2, AE1/3, keratin 903, desmin, vimentin, HHF-35, CEA, PLAP, NSE, S-100, HMB45, LCA, L26 and UCHL-1. Twenty-three fresh epithelial and mesenchymal tissues from the uterus, colon, tonsil, lymph node, kidney and adrenal gland were examined, along with 29 tumors. There were 21 carcinomas, 3 melanomas, 3 sarcomas and 2 lymphomas. Using the streptavidin-biotin technique with aminoethylcarbazole localization, IPX results were available in 15-20 minutes, comparable to the time required for the reporting of a frozen section diagnosis. Keratins, vimentin, desmin and LCA gave the best results. HMB45 was weakly reactive in one case. This rapid cytologic IPX method may be used as an adjunct to frozen sections and cytologic imprints for intraoperative diagnosis or for efficient triage of poorly differentiated tumors for special studies at the time of frozen section.