Thyroid Lesion Reporting using the TBSRTC System: Cytohistopathological Correlation in a Tertiary Care Hospital Experience

Background: Thyroid lesions are prevalent endocrine disorders with an increasing incidence globally. Accurate diagnosis is critical for guiding appropriate management strategies. Fine-needle aspiration cytology (FNAC) is widely used for initial evaluation, and the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) provides a standardized classification system for FNAC results. Despite its widespread adoption, the diagnostic accuracy of FNAC varies across different clinical settings, necessitating ongoing evaluation and refinement. Aim: This study aimed to evaluate the diagnostic accuracy of FNAC in thyroid lesion reporting using the TBSRTC system and to assess the cytohistopathological correlation in a multicentric setting. Methods: This was a multicentric, observational, and retrospective study conducted over 24 months, including 315 patients who underwent FNAC followed by histopathological examination after surgical resection of thyroid lesions. FNAC results were categorized using the TBSRTC system, and their correlation with histopathological findings was analyzed. Statistical analysis was performed using SPSS version 23.0 to calculate sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy. Results: The study included 315 patients, with a mean age of 45.2 years and a female predominance (74.6%). FNAC results were categorized as benign in 57.1% of cases, with 78 cases (24.8%) histopathologically confirmed as malignant. FNAC demonstrated a sensitivity of 80.6%, specificity of 91.8%, PPV of 81.6%, NPV of 91.3%, and an overall accuracy of 87.0%. The kappa coefficient of 0.75 indicated substantial agreement between FNAC and histopathological findings. Conclusion: FNAC, categorized by the TBSRTC system, is a reliable diagnostic tool for thyroid lesions, particularly effective in ruling out malignancy. However, the moderate sensitivity highlights the need for careful follow-up in cases with indeterminate or benign cytology. The findings underscore the importance of histopathological confirmation, especially in cases with clinical suspicion of malignancy despite benign cytology. Recommendations: Further studies should focus on improving the diagnostic accuracy of FNAC in indeterminate cases and exploring advanced techniques to complement FNAC in thyroid lesion evaluation. Regular training and quality control measures are recommended to enhance the consistency and reliability of FNAC results across different clinical settings.