Abstract Background and Objectives: The Bethesda system for reporting thyroid cytopathology (TBSRTC) is a standard method for analyzing thyroid smears, there by communicating clear and relevant information to the clinician. Objective of the study is to classify the cytological features of different thyroid lesions according to TBSRTC and compare them with histopathology wherever possible and to determine the diagnostic accuracy. Materials and Methods: A prospective fine needle aspiration (FNA) study is conducted in the department of pathology VIMS Ballari on all cases of thyroid lesions between January 2015 and June 2016. The smears are classified using the Bethesda system and distribution in each category is done. The malignancy risk for each category is calculated by follow up histopathology wherever possible. Results: Of the 300 FNA of thyroid swelling 10.66% were nondiagnostic, 77% were benign, 5.6% were atypical follicular lesions of undetermined significance(AFLUS), 4% were suspicious for follicular neoplasms, 1.33% were suspicious for malignancy and 1.33% were malignant. Follow up histopathological examination(HPE) are available in 70 cases. The distribution of malignancy risk rates in various Bethesda category were 11.11% in nondiagnostic, 2.08% in benign. 66.67% in atypical FLUS, 0% in follicular neoplasms, 100% in suspicious of malignancy and 100% in malignant category. Conclusion: The implementation of TBSTRC which stands for a unique, international and a universal terminology for the reporting of the thyroid cytology should be encouraged because of its relative ease of reproducibility. The classification is directly related to the risk of malignancy in each category which in turn prompts the recommended clinical management of that category.
Keywords: Bethesda System; Fine Needle Aspiration; Histopathology; Thyroid Lesions