Accuracy of fine needle aspiration cytology and thyroid imaging reporting and data system to predict the nature of nodular goiter and its comparison with postoperative histology

Abstract

Background: Aim of the study was to find accuracy of pre-operative fine needle aspiration cytology (FNAC) and thyroid imaging reporting and data system (TIRADS) in predicting the nature of nodular goitre and confirming it with post-operative biopsy. Objective of the study was to assess the sensitivity and specificity of FNAC compared with post-operative biopsy and to assess the sensitivity and specificity of TIRADS compared with post-operative biopsy.Methods: This retrospective study was carried out at tertiary hospital, King George Hospital, Visakhapatnam over a period of 1 year from march 2018 to march 2019. Sensitivity and specificity are calculated based on formulae.Results: Sample size calculated with 90% confidence interval for population of vizag is 96, a sample of 100 patients were taken in this study. Of the 100 cases, 16 had thyroid carcinoma. 15 of them were papillary carcinoma and 1 follicular carcinoma. 8 cases matched with cytology report after post op biopsy and 8 we mismatched with cytology report after post op biopsy. The incidence of malignancy in clinically and cytologically benign goitre is 8.69. In our study sensitivity of FNAC is 50%, specificity is 100% and accuracy of test is 92% and TIRADS has a sensitivity of 100% and specificity of 72.62% and an accuracy of 77%.Conclusions: The current study has showed the disparity we see in thyroid neoplasms in FNAC test and TIRADS, which were proved to be different diagnosis in clinical and histopathology, so even if cytology is benign, we can’t rule out malignancy. FNAC and TIRADS combined have more sensitivity and specificity than individual tests.