Categorization of lymph node aspirates based on ‘The Sydney system for reporting lymph node cytology’ – A four-year retrospective study

Abstract

Background: Lymph node aspirate cytopathology lacks a uniform reporting format due to the multitude of diseases it encompasses. To address this issue, The Sydney system was introduced to improve the reporting of lymph node cytopathology, with five diagnostic categories to standardize the reporting of lymph node fine needle aspirates. Our study aimed to assess the risk of malignancy associated with each diagnostic category of the Sydney system.

Materials and Methods: The present study is a retrospective cross-sectional analysis of lymph node aspirates obtained through fine-needle aspiration cytology over the past four years. The aspirates were categorized using The Sydney System into five groups from L1 to L5. To measure the risk of malignancy for each diagnostic category, the diagnoses were correlated with the corresponding histopathological diagnoses wherever available. The statistical tools used were sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and risk of malignancy.

Results: 238 cases of lymph nodes FNACs were recorded. These were grouped into five categories using the Sydney system L1(16), L2(148), L3(20), L4(18), and L5(36). Out of these 238 cases, histopathology correlation was available only for 60 cases, which included three cases in L1, 28 cases in L2, four cases in L3, nine cases in L4, and 16 cases in L5 categories, and the risk of malignancy were found to be 0%, 3.57%, 75%, 100%, and 100% for L1, L2, L3, L4, and L5 categories, respectively.

Conclusions: The findings of this study highlight the significant role of the Sydney system in enhancing the reliability of lymph node cytological diagnoses. The Sydney system helps pathologists to standardize reporting for better clinical and surgical management.