Background

The Sydney system for reporting lymph node cytopathology has developed a uniform system of reporting lymph node aspirates by classifying them into five categories- Non-Diagnostic (ND), Benign (B), Atypical cells of Undetermined Significance / Atypical lymphoid cells of uncertain significance (AUS/ ALUS), Suspicious for Malignancy (SFM) and Malignant (M). Very few studies have been conducted so far to confirm the risk of malignancy of the different categories.

The main objectives of our study were to classify lymph node aspirates according to the proposed Sydney System and assess risk of malignancy and performance parameters.

Materials and Methods

All lymph node aspirates done from January 2018 to December 2020 were reclassified according to the Sydney system. Using histopathological diagnosis as gold standard, risk of malignancy (ROM) and performance parameters were calculated.

Results

1205 lymph node aspirates were reclassified: 53(4.4%) ND, 488 (40.5%) B, 10 (0.8%) AUS/ ALUS, 275 (22.8%) SFM and 379 (31.5%) M. The ROM for each of the aforementioned categories was 9.1%, 1.5%, 37.5%, 96.9% and 98.2% respectively. The highest sensitivity was achieved when AUS/ ALUS, SFM and M are considered positive whereas maximum diagnostic accuracy was observed when SFM and M are considered positive for malignancy.

Conclusion

The Sydney system is an excellent system for accurately categorizing lymph node aspirates with greater reproducibility of reports and better patient management through improved communication between cytopathologist and clinician.