Evaluation of diagnostic utility of EMA in differentiation between reactive mesothelial versus metastatic adenocarcinoma cells inserous cavity fluid

Background:The cytological diagnoses of serous effusions are usually made by routine cytomorphologywith certainty. However, overlapping cases sometimes exist between reactive mesothelial andadenocarcinoma cells.We tried to evaluate the diagnostic utility of EMA monoclonalantibody in distinguishing between reactive mesothelial cells and adenocarcinoma in serouseffusions.Materials and Methods:Paraffin blocks and H&E stained slides of peritoneal and pleural fluid cell blocks wereretrieved from cytology archive of Alzahra Hospital, Medical University of Isfahan,between2006 and 2010. From among 1025 slides which were screened to ascertain their appropriatediagnoses.Among of these 90 paraffin embedded cell blocks,30 cases for adenocarcinomaand 60 cases for reactive mesothelial groups were selected for immunocytochemistrystaining. Cellular reactivity, intensity and pattern of staining for EMA was evaluated by usinganti-human epithelial membrane antigen clone E29 . Statistical analysis and tests ofsignificance were performed using SPSS software.Results:The mean age of the patients in the reactive mesothelial and adenocarcinoma groups were50.28 and 55.16 years, respectively. The gender distribution for malignant group included 22cases (%73.33) female and 8 cases (26.66%) male.This ratio for reactive group included 16cases (26.66%) and 44 cases (73.33%). The mean of immunoreactive cells for EMA inadenocarcinomatous cells was: 97.5 (SD=7.62) and in reactive mesothelial cells was: 21.6(SD= 30.43) (p=0.001). The severe immunoreactive cases for metastatic adenocarcinomagroup was: 30 cases(100%) and for reactive mesothelial group was:8 cases(13.33%)(P=0.001).Conclusion:Immunocytochemical staining for EMA is a useful diagnostic tool for distinguishingeffusions containing malignant cells from those that contain benign cells, and in particular,we suggest that the precise evaluation of pattern and intensity of immunoreactive cells forEMA is extremely useful.

کلیدواژه ها:

EMA ، adenocarcinoma ، reactive mesothelial ، serous effusion