A STUDY ON DIAGNOSTIC UTILITY OF CELL BLOCK METHOD VERSUS CONVENTIONAL SMEAR STUDY IN PLEURAL AND PERITONEAL FLUID CYTOLOGY

Abstract

The cytological examination of serous fluids like pleural and peritoneal effusions are well accepted and their positive diagnosis is mostly considered as a definitive diagnosis. It is helps in staging, prognosis, management of patients with malignancies, and it also gives the information about various inflammatory and non-inflammatory lesions. Routine conventional methods have a limitation in differentiating between reactive mesothelial cells and malignant cells Thus Cell Block method overcomes these limitations because of its increased cellularity, preservation of tissue architecture and feasibility of performing immunohistochemistry. This paper aims to compare the sensitivity, specificity and positive predictive value (PPV) of cell blocks and conventional smears of pleural and peritoneal fluid specimens in diagnosing malignancy and to calculate the efficacy of cell blocks in typing malignancy. This study was conducted to compare the diagnostic efficacy parameters of cell block method and routine conventional smears in pleural and peritoneal fluids in the cases of suspected malignancy.  A one year study was done in a Government Medical College on pleural and peritoneal fluids over the suspected cases of malignancy. The total number of cases studied were 140, while specimens taken were a total of 160 pleural and peritoneal fluids. The cytology smears were stained with Papanicolaou stain and cell block preparations of centrifuged deposits were processed, cut at the size of 5 micrometers and the sections were stained by Hematoxylin and Eosin in every case. In the cell blocks slides additional stains and immunohistochemistry were done as required. Diagnosis of malignancy for any tissue based method within a period of 3 months of follow up was taken as the gold standard for analyzing the results. Sensitivity of cell blocks being 0.6521 was closed to double to that of routine cytological smears which was 0.2879. Both the methods were very high in specificity. Cell block method was proved to be superior to conventional smears in terms of pattern recognition and have more advantage whenever there is need for immunohistochemistry. The use of cell blocks in adjunct with conventional cytological smears of body fluids can increase the sensitivity to a considerable extent. It is used further in affirming the diagnosis by pattern recognition or immunohistochemistry.

Keywords: Cell block method, Conventional smear method, Pleural effusion, Peritoneal effusion, Sensitivity