Immunohistochemical Study on Cell Block of Ascitic Fluid to Ascertain the Etiology

Cytological examination of body fluids is important for the diagnosis, staging and assessment of prognosis in malignant lesions. Based on morphologic features alone, cytological differentiation of reactive mesothelial cells from adenocarcinoma is found to be difficult. Therefore, ancillary studies often are performed to assist in the differential diagnosis. We have done this study to evaluate the validity of combined approach of routine cytological staining methods and cell block techniques along with immunohistochemistry on cell block sections in differentiating adenocarcinoma cells from reactive mesothelial cells. The study was conducted in a tertiary care hospital over the period of two years, September 2014 to august 2016. Ten millilitres of 250 fresh ascitic fluid samples from patients who were taken for conventional cytological examination. Suspicious samples are processed to cell block. Immunostaining with Calretinin, Cytokeratin7, Cytokeratin20 done for differentiating adenocarcinoma cells from reactive mesothelial cells & metastatic adenocarcinoma. Chi-Square Test proved increased diagnostic yield. There is 3.3% more cases are diagnosed as malignant after histological study on cell block. So, there will be no necessity to give a diagnosis of suspicious of malignancy or equivocal for malignancy. We had studied histology in 55 cases, out of which 44(80%) cases yields superior diagnosis after cyto-histological & immunohistochemical correlation. We recommend combined use of cytology on conventional smears with cell block & immunohistochemistry for suspicious or malignant ascitic cases to raise diagnostic accuracy as much as possible.