UTILITY OF THE SYDNEY SYSTEM FOR REPORTING OF LYMPH NODE CYTOLOGY IN A TERTIARY HEALTH CARE SET UP OF NORTH-EASTERN INDIA

Objective: Fine Needle Aspiration Cytology (FNAC) is a popular method for diag-nosing lymphadenopathy. The Sydney system for lymph node cytology classification and reporting has been developed for unified reporting language among cytopathologists and clinicians. The purpose of this study was to determine the system's applicability and accuracy in the diagnosis of lymph node cytology.Patients and Methods: This was a retrospective cross sectional study of lymph node cytology conducted from January 2018 to July 2021, and the results were reported using the Sydney System into 5 groups from L1 to L5. To measure diagnostic accuracy and the risk of malignancy for each diagnostic category, the diagnoses were compared with the corresponding histological diagnoses. The statistical tools used were calculation of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and risk of malignancy (ROM).Results: A total of 220 cases were chosen for the study from a total of 600 FNACs performed for lymphadenopathy since they had histological correlation. The L1, L2, L3, L4, and L5 categories were assigned to 7 (3.18%), 141 (64.09%), 44 (20%), 8 (3.63%), and 20 (9.09%) cases, respectively. Malig-nancy risk was determined to be 33.33%, 8.8%, 56.4%, 83.33%, and 94.74% for the various groups. Conclusions: The proposed Sydney system of reporting and classification of lymph node cy-tology can help in achieving uniformity and reproducibility. This appears to be the first time, the Sydney system has been introduced in this region in routine patient care, and this has improved the clinicians' understanding of the risk of malignancy and subsequent care.