Correlation between Thyroid Imaging Reporting and Data System and Bethesda System of Reporting of Thyroid Cytopathology of Thyroid Nodule: A Single Center Experience

BACKGROUND: The incidence of thyroid cancer has been increasing worldwide. Thyroid imaging reporting and data system (TIRADS) has been proposed for risk stratification of thyroid nodules to improve categorical management. Fine needle aspiration cytology based on Bethesda system for reporting of thyroid cytopathology (BSRTC) plays a fundamental role in the evaluation of thyroid nodule microscopically. Both the systems, the TIRADS and the latest revised BSRTC 2017, are widely recommended and practiced all over the world, but the correlation between the two systems has not been established. AIMS AND OBJECTIVES: This study was conducted to assess the risk of malignancy (ROM) in the intermediate Bethesda categories of thyroid lesions and their correlation with the corresponding TIRADS categories. MATERIALS AND METHOD: It was a prospective cross-sectional study over 1 year including 69 patients aged 18 years or older having solitary thyroid nodules. All cases were triaged using both TIRADS and BSRTC 2017 and the diagnostic performances were compared with subsequent paraffin sections to evaluate ROM. Correlation between TIRADS and BSRTC systems was expressed as kappa value. RESULT: Good concordance was observed between TIRADS and BSRTC systems in the evaluation of benign thyroid nodule lesions (category 2-II). There was discordance in follicular lesions (category 4-IV). The kappa value generated (0.411) revealed moderate agreement between the two risk stratification systems. CONCLUSION: Careful application of both grading systems is essential for the proper segregation of thyroid nodules to facilitate effective clinical and surgical management. However, universally acceptable protocols need to be developed to avoid the heterogeneous approach.