1Department of Pathology, Pandit Raghunath Murmu Medical College and Hospital, Baripada, 757107, Odisha, India
2Department of Pathology, JK Medical College and Hospital, Jajpur, 755001, Odisha, India
3Department of Pathology, Pandit Raghunath Murmu Medical College and Hospital, Baripada, 757107, Odisha, India
4Department of Pathology, Pandit Raghunath Murmu Medical College and Hospital, Baripada, 757107, Odisha, India
5Department of Pharmacology, Pandit Raghunath Murmu Medical College and Hospital, Baripada, 757107, Odisha, India
6Multi-Disciplinary Research Unit, Pandit Raghunath Murmu Medical College and Hospital, Baripada, 757107, Odisha, India
*Corresponding Author E-mail: dratanubal1974@yahoo.co.in
Lymphadenopathy diagnosis requires accurate tools like FNAC. The Sydney System was introduced to standardize reporting, but diagnostic variability persists, necessitating localized validation. This study aimed to evaluate the Sydney System's diagnostic accuracy, sensitivity, specificity, PPV, and NPV for lymph node lesions. A two-year cross-sectional study (Nov 2022-Oct 2024) at PRM Medical College and Hospital analyzed 448 non-guided lymph node FNAs. Cases with histopathological or comprehensive clinical/radiological followup were included. Two cytopathologists independently categorized smears using the five-tiered Sydney System (L1-L5), integrating ancillary study results. Statistical analysis determined diagnostic metrics and Risk of Malignancy (ROM).The 21-30 age group had the most cases (31.25%). Cervical (33.92%) and unusually high supraclavicular (23.21%) lesions were common, the latter strongly correlating with malignancy. Sydney System categorization showed balanced benign (43.75%) and malignant (41.9%) diagnoses. Granulomatous lymphadenitis was frequent benign; metastatic squamous cell carcinoma and Non-Hodgkin Lymphoma (NHL) were common malignancies. ROM for Category III (Atypical) was 66.67%, with all malignant cases confirmed as NHL. Category IV (Suspicious) showed an 80% ROM. Notably, non-diagnostic Category I had a 33.33% ROM. Overall diagnostic performance was high: sensitivity 91.49%, specificity 93.10%, PPV 95.56%, NPV 87.10%, and accuracy 92.11%,. This study provides compelling evidence for the Sydney System's robust diagnostic accuracy and utility in risk-stratifying lymph node lesions. Key insights include the high ROMs for indeterminate categories (especially NHL in Category III) and the significant risk associated with non-diagnostic samples, guiding clinical management. The research confirms the Sydney System's value as a standardized tool for clinical practice.
Fine needle aspiration cytology, Lymphadenopathy, Sydney System Cytological Diagnosis
