The Bethesda system for reporting thyroid FNAC: A cytohistological correlation in a newly established institute

Introduction: FNAC is an excellent modality for diagnosis of thyroid lesions because of its simplicity and cost effectiveness. Since the introduction of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) in 2007, it has become a standardized, convenient and more informative system of thyroid reporting. Aims: 1. To study cytological features of FNAC and categorization according to TBSRTC; 2. To assess statistical analysis of FNAC in detecting malignant lesions. Settings and Design: This is a cross-sectional study carried out in the Pathology Department from January 2015 to December 2017. Materials and Methods: We interpreted 329 thyroid FNAC and categorized them according to TBSRTC. 75 cases are correlated histologically. Statistical Analysis: Accuracy, specificity, sensitivity and predictive values. Result: Distribution of different categories are as follows Non-diagnostic/unsatisfactory (ND/UNS)-8.5%, Benign-85.2%, Atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS)-0.6%, Follicular neoplasm/suspicious for follicular neoplasm (FN/SFN)-2.4%, Suspicious for malignancy (SFM)-1.5% and malignant-1.8%. The malignancy risk calculated from histopathological follow up of 75 cases is as follows: ND/UNS 0%, Benign 6.9%, FN/SFN 16.7%, SFM 66.7% and malignant 100%. The positive predictive value, negative predictive value and accuracy of TBSRTC are 100%, 93.1%, 93.7% respectively. Conclusion: The malignancy risk, accuracy, specificity and predictive values are consistent with other studies. Thus TBSRTC allows more standard reporting, specific diagnosis and understanding of terminology between pathologists and clinicians.