Risk Assessment of Diagnostic Categories in the Proposed Sydney System for Reporting Lymph Node Cytopathology: A Retrospective Cytomorphological Study

Background & Objective: Fine-needle aspiration cytology (FNAC) is a minimally invasive, rapid, and relatively safe diagnostic method for the initial evaluation of lymphadenopathy of unknown origin. In May ۲۰۲۰, the Sydney System was proposed to provide recommendations for diagnostic categorization, FNAC of lymphadenopathy, pathology reporting, and related practices. This study aimed to analyze the applicability of the Sydney System in lymph node FNAC and to evaluate diagnostic accuracy and risk of malignancy (ROM) for each diagnostic category.Methods: A ۲-year retrospective diagnostic study was conducted from January ۲۰۱۹ through December ۲۰۲۰. Sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy (DA), and ROM were calculated using histopathology as the gold standard.Results: A total of ۶۳۲ lymph node FNAC cases were included, with histopathological follow-up available in ۴۵ cases. The median age of patients was ۲۶ years, with a male-to-female ratio of ۱.۲:۱. Cervical lymph nodes were most frequently involved (۳۶۷ cases, ۵۸.۱%). Overall sensitivity, specificity, and diagnostic accuracy were ۶۶.۷%, ۸۵.۰%, and ۷۶.۳%, respectively. ROM by diagnostic category was: nondiagnostic (۲۵%), benign (۵.۲%), atypia of undetermined significance (AUS) (۵۰%), suspicious (۸۰%), and malignant (۸۸.۸%).Conclusion: FNAC demonstrated high diagnostic efficacy when applied using the proposed Sydney System, supporting the utility of this standardized reporting scheme for lymph node cytology.

کلیدواژه ها:

Fine-Needle Aspiration ، Lymphadenopathy ، Malignancy ، retrospective ، Diagnostic Accuracy