Are We Operating Smarter? Risk of Malignancy Across Bethesda Categories-A 10-Year Institutional Experience.

Abstract

The global incidence of thyroid cancer has risen over recent decades, largely attributed to increased detection of thyroid nodules. This trend has raised concerns regarding overdiagnosis and overtreatment. The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) plays a pivotal role in preoperative risk stratification, yet clinical decision-making remains challenging in indeterminate categories (Bethesda III-V), particularly in resource-limited settings where molecular testing is unavailable. To determine the risk of malignancy (ROM) for each TBSRTC category among patients who underwent thyroid surgery over a 10-year period at a tertiary care center in India, and to compare these rates with the 2023 TBSRTC risk estimates. This retrospective study analyzed fine-needle aspiration cytology and histopathology data for all patients who underwent thyroid surgeries conducted between 2014 and 2024. ROM across TBSRTC categories was calculated and compared with established TBSRTC risk estimates. A 100% malignancy rate was observed in TBSRTC VI category, supporting the reliability of surgical decisions in this group. However, significantly higher malignancy rates were found in TBSRTC categories III (58.7%), IV (82.7%), and V (100%) compared to TBSRTC estimates (22%, 30%, and 74%, respectively). TBSRTC III nuclear had a significantly higher malignancy rate (70.0%) than TBSRTC III other (40.57%). Institution specific malignancy data enhances the clinical utility of TBSRTC and improves patient counseling, particularly in settings where molecular diagnostics are not feasible.