The combination of thyroid imaging reporting and data system (TIRADS) and The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) in the evaluation of thyroid nodules - An institutional experience.

BACKGROUND The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is being widely practiced by cytopathologists. Thyroid imaging reporting and data system (TIRADS) for thyroid nodules proposed by American college of Radiology (ACR) to classify thyroid nodules and to guide the nodule selection for FNAC. The study aimed to analyze the usefulness of TBSRTC in thyroid cytology reporting, to establish the histological correlation of TIRADS, and to compare the management of lesions in each cytological category in our institute to that recommended by TBSRTC. MATERIALS AND METHODS A retrospective study was performed on all thyroid FNAs reported during the two-year study period in a tertiary care center. The histological correlation of TBSRTC and ACR TIRADS was done for cases with surgical follow-up and risk of malignancy in each category, sensitivity and specificity of FNA and TIRADS were calculated. RESULTS A total of 337 thyroid FNAs were performed of which histological follow up was possible for 99 cases. Risk of malignancy in each category from I to VI was 9.5%, 2.3%, 0, 8%, 87.5% and 100% respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of FNA were 60%, 99%, 85.7%, and 97.5% respectively. The sensitivity, specificity, positive and negative predictive value of thyroid ultrasound were 90.28%, 72.2%, 92.86% and 65% respectively. CONCLUSION The study substantiates the usefulness of TBSRTC in arriving at a more precise diagnosis. Hurthle cell lesions with atypia were the common cause of misdiagnosis. The combination of TIRADS and TBSRTC aids in better stratification of thyroid nodules. The Bethesda system of reporting thyroid cytopathology, thyroid nodules, atypia of undetermined significance, papillary carcinoma.