Comparison of the Cell Block Technique with Conventional Cytology Smear in Serous Effusions

Background; Serous effusion cytology is an important minimally invasive investigation for the evaluation of benign, reactive and malignant conditions. Conventional cytological smears provide information regarding individual cell morphology, whereas cell block preparation may improve cellular concentration and architectural assessment and provide additional material for ancillary investigations. Aim; To compare the cellular preservation and diagnostic findings obtained by conventional cytology smear and cell block techniques in serous effusions. Materials and Methods; An observational comparative study was conducted in the Department of Pathology, Bharati Vidyapeeth Medical College, Sangli, Maharashtra, from February 2023 to July 2023. A total of 100 serous effusion specimens comprising pleural, peritoneal and pericardial fluids were included. Each specimen was divided into two portions. One portion was processed by conventional smear cytology and the other by cell block technique. Conventional smears were prepared from centrifuged sediment and stained with H&E. For cell block preparation, the sediment was fixed in 10% formalin, processed by routine tissue-processing methods and stained with H&E. Cellular preservation and diagnostic categorization were compared. Results; Of the 100 specimens, 56 (56.0%) were pleural, 36 (36.0%) peritoneal and 8 (8.0%) pericardial. Preserved cellularity was observed in 68 (68.0%) conventional smears and 88 (88.0%) cell blocks. Conventional smears were categorized as benign in 70 (70.0%), suspicious in 18 (18.0%) and malignant in 12 (12.0%) cases. Corresponding cell-block findings were benign in 64 (64.0%), suspicious in 10 (10.0%) and malignant in 26 (26.0%) cases. The combined suspicious/malignant category was 30.0% with conventional smear and 36.0% with cell block. Conclusion; Cell block preparation showed better cellular preservation and identified a higher proportion of malignant diagnoses than conventional smear examination in the present study. Both techniques can be considered complementary approaches for the cytological evaluation of serous effusions.