Implementation of the Bethesda system of reporting thyroid cytopathology in a referral center

Abstract

Introduction: The introduction of the Bethesda System of Reporting Thyroid Cytopathology (TBSRTC), following the “National Cancer Institute Thyroid Fine-Needle Aspiration State of the Science Conference” held in Bethesda, in 2007, offered the opportunity to establish a uniform six-tiered reporting system for thyroid fine-needle aspiration (FNA). Aim of the Study: The aim of the study was to implement and to evaluate the diagnostic accuracy and risk of malignancy (ROM) of categories of TBSRTC. Materials and Methods: FNA was taken from the thyroid swelling during the study period and smears were stained with hematoxylin and eosin, Diff-Quik, or papanicolaou stains. Nodular thyroid swelling cases were subjected to histopathological correlation. Results: Of the 1724 FNAs, a total of 223 cases of palpable nodular thyroid swelling were studied with cytohistopathological correlations. About 13.90% of the cases were diagnosed as malignant. The ROM for Bethesda Category V and VI was 100% each, whereas it was 47.62%, 10%, and 2.82% for Category III, IV, and II, respectively. The overall sensitivity, specificity, positive predictive value, negative predictive value, and the diagnostic accuracies of TBSRTC were 83.87%, 89.58%, 56.52%, 97.18%, and 88.79%, respectively. Conclusion: In our study, a more specific cytologic diagnosis was offered based on criteria laid down in the standardized nomenclature of the Bethesda System 2018 citing diagnostic accuracy and ROM in each category.