Correlation of Fine Needle Aspiration Cytology of Thyroid Gland with Histopathological Results

Fine needle aspiration cytology (FNAC) is considered as the gold-standard diagnostic test in the diagnostics of thyroid nodules. It is a cost-effective procedure that provides specific diagnosis rapidly with minimal complications. It plays an important role in the determination of treatment - patients with suspected malignancy diagnosis can be subjected to surgery. On the other hand, it can decrease the rate of unnecessary surgeries. Aim: The aim of this study was to evaluate and compare the correlation, accuracy of fine needle aspiration cytology (FNAC) in the diagnostics of thyroid lesions with the final histopathologic diagnosis based on the surgical specimens. Materials and Methods: In our study we performed a retrospective analysis of a case series of patients who had been admitted to the Department of Endocrine, General and Oncological Surgery of the Hospital of M. Kopernik in Łodź (Poland) between May 2016 and December 2017 and underwent FNAC with subsequent surgery. Cytological diagnosis was classified into six Bethesda categories. Results: On cytological examination, 1070/1262 cases were reported as benign, 49 as malignant and 143 as suspicious. On histopathological examination, 956/1070 cases were confirmed as benign but there were 114 discordant cases. Among the other cases histopathology diagnosis confirmed malignancy in 45/49 cases and 128/143 suspicious cases. The sensitivity and specificity were 60,28% and 98,05% respectively. False positive rate was 1.95% and false negative rate was 39.72%. The positive predictive value was 90.1% and negative predictive value was 89.35%. Accuracy of FNA in differentiating benign from malignant thyroid lesions was 89.46%.