Effectiveness of International System for Reporting Serous Fluid Cytology in Routine Practice – A Cross Sectional Study at a Tertiary Care Centre

Abstract

Background: To standardize the reporting pattern across various institutions, recently the international system for reporting serous fluid cytology (ISRSFC) was introduced. The objective of the present study was to classify serous fluids into various categories as per the ISRSFC, derive the risk of malignancy for each category and determine the diagnostic efficacy of fluid cytology when ISRSFC was applied. Methodology: Cross-sectional study involving 235 cases of serous effusion over a duration of two years. All the cases were reclassified as per ISRSFC into five categories. Descriptive statistics was derived. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) was determined in 74 cases wherein final diagnosis was confirmed by clinical findings, radiology, or cell block. Results: Out of total 235 cases of fluid examined, distribution of cases in the diagnostic categories were as follows, 11 (4.6%) in nondiagnostic (ND), 208 (88.51%) in negative for malignancy (NFM), 5 (2.12%) in atypia of undetermined significance (AUS), 2 (0.85%) in suspicious for malignancy (SFM) and 9(3.82%) in malignant (MAL)category. Out of 208 cases of NFM, mesothelial cells were seen in only 8 (3.8%) cases. The risk of malignancy was 0% each in ND and NFM, 40% in AUS, 100% each in SFM and MAL. Sensitivity and specificity of fluid cytology was 100% and 96.6% respectively while PPV and NPV was 81.81% and 100 % respectively. Conclusion: ISRSFC is easy to apply and has high diagnostic efficacy. Most of the serous effusions fall in negative for malignancy category. Mesothelial cells are not important for specimen adequacy.

Keywords

• fluid cytology
• risk of malignancy
• serous
• effusions