Abstract
Aim: To study the diagnostic accuracy of fine needle aspiration cytology (FNAC) and intraoperative frozen section (IOFS) for thyroid nodules.
Methods: We reviewed the medical files of 63 patients who underwent surgery for thyroid nodule between January 2016 and December 2019 at our department. All patients included in the study were subjected to both FNA (fine needle aspiration) and intraoperative frozen section (IOFS). We evaluated the sensitivity, specificity, positive and negative predictive value of each of these studies.
Results: The FNAC diagnosis was Bethesda I in 7 cases, Bethesda II in 16 cases, Bethesda III in 19 cases, Bethesda IV in 6 cases, Bethesda V in 5 cases, and Bethesda VI in 10 cases. The malignancy rate was 44%. The malignancy rate for each Bethesda category was: Bethesda II, 2/16 (12.5%), Bethesda III 57%, Bethesda IV 50%, Bethesda V, 100%, and Bethesda VI 70%. The sensitivity, specificity, positive and NPV values for FNAC were respectively 85.7%, 82.3%, 80% and 87.5%. The sensitivity, specificity, PPV and NPV values for IOFS were respectively 42.3%, 100%, 100% and 68%.
Conclusion: Our data showed that FNAC had a better sensitivity and negative predictive value, while the IOFS examination had a better specificity for predicting malignancy. Both FNAC and IOFS are useful in the management of thyroid nodules.
Key words: Thyroid, Thyroid nodule, Fine needle aspiration (FNA), Cytopathology, Thyroid tumor, Ultrasound
