New diagnostic technique for rapid fluorescence immunocytochemical staining of adenocarcinoma and mesothelial cells using liquid-based cytology.

OBJECTIVE To evaluate the expression of antibodies against calretinin, cytokeratin 5/6, desmin, D2-40, HBME-1, mesothelin, thrombomodulin, WT1, Ber-EP4, CEA, EMA and MOC-31 individually and to compare it with a new rapid procedure for fluorescence immunocytochemistry (ICC) using liquid-based cytology (LBC). STUDY DESIGN Sixty-four peritoneal cell specimens prepared with the LBC method were stained with these markers to evaluate their usefulness and develop a rapid fluorescence immunostaining method using Ber-EP4 that is applicable to intraoperative cancer cytodiagnosis. RESULTS The adenocarcinoma markers were positive in 92% of adenocarcinoma cases, 57% of cases with suspicion of adenocarcinoma, and 5% of negative cases (reactive mesothelial cells). On the other hand, the mesothelial cell markers were positive in 8-15% of adenocarcinoma cases, 43-57% of cases with suspicion of adenocarcinoma, and 93-95% of negative cases. The rapid new fluorescence ICC procedure clearly stained only the adenocarcinoma cells within 20 min. CONCLUSION Immunocytochemical examination with the LBC method is a powerful ancillary technique for discriminating adenocarcinoma cells from mesothelial cells. This rapid new fluorescence ICC procedure can be used as an ancillary technique for accurate detection of adenocarcinoma cells in the intraoperative cytological examination of peritoneal or pleural washing fluid.