The Role of Novel Tiered Reporting System in Serous Fluid Cytology and Risk of Malignancy Assessment: A Retrospective Study in a Tertiary Care Center

Background: Serous effusion cytology (SEC) reporting is important for the management of the cancer patient. The International System for Reporting Serous Fluid Cytology (ISRSFC) provides tiered reporting terminology to standardize practice, looking into the risk of malignancy (MAL) for each category. In this study, we have assessed the utility of the ISRSFC and reported our experience at a tertiary cancer center. Materials and Methods: Serous fluid cytology reported from January 2019 to December 2020 was categorized according to ISRSFC diagnostic categories: nondiagnostic (ND), negative for MAL (NFM), atypia of undetermined significance (AUS), suspicious for MAL (SFM), and MAL. The risk of MAL (ROM) and performance parameters were calculated. Results: A total of 2150 serous effusions including 1160 pleural, 929 peritoneal, and 61 pericardial effusions from 2071 patients were reported. There were 742 males and 1329 females. The patient’s age ranged from less than 1 yr to 95 years. The volume of the sample ranged from 0.5 ml to 2000 ml. There were 114 ND (5.32%), 1068 NFM (49.67%), 144 AUS (6.69%), 82 SFM (3.81%), and 742 MAL (34.51%) cases. Adenocarcinoma was the most common MAL involving serous fluids (91.50%). The calculated ROM was 15.38% for ND, 24.26% for NFM, 62.96% for AUS, 79.16% for SFM, and 100% for MAL. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were, respectively, 68.04%, 96.96%, 96.35%, 72.07%, and 81.33%. Conclusion: ISRSFC provides consistent reporting terminology and the ROM for each category aids in clinical correlation and management.