The Bethesda System for reporting thyroid cytopathology: A two year retrospective review in a tertiary care hospital

Background: The Bethesda system for reporting thyroid cytopathology (TBSRTC) has standardized our diagnostic approach to cytomorphological criteria and reporting. Aims: To study retrospectively the diagnostic utility of TBSRTC at our institution and to correlate the cytopathology and histopathology. Materials and methods: We retrospectively reviewed thyroid FNA between 2012 and 2014, classified according to the Bethesda system, found out the distribution of cases in each category, analysed the risk of malignancy in each category by the histopathology report and compared with other studies. Results: The distribution of various categories from 402 FNA of thyroid nodules was as follows: 10.7% non-diagnostic, 81.6%benign, 1.27% atypia of undetermined significance (AUS/FLUS), 1.74% suspicious for follicular neoplasm, 2% suspicious for malignancy and 2.7% malignant. Follow-up histopathologic examination was available for 92 cases. Sensitivity, specificity; positive predictive value and negative predictive value were calculated. Risk of malignancy was 28.6% for suspicious for neoplasm (SFN) category and 71.4% for suspicious for malignancy (SFM) category. Conclusions: TBSRTC is an excellent reporting system for thyroid FNA. The malignancy risk correlates well with previous studies. It provides clear management guidelines to clinicians to go for follow-up FNA or surgery and the extent of surgery. Key words: Fine needle aspiration cytology, Bethesda system, histopathology and thyroid nodule