Utility of Surgeon Performed Ultrasound Guided Fine Needle Aspiration Cytology for Diagnosis of Thyroid Nodules

Abstract

Background: The incidence of thyroid malignancy is increasing globally and this results in the growing number of patients facing increasing wait times for ultrasound (US) guided fine needle aspiration cytology (FNAC) for diagnosis. The objective of this study is to investigate the accuracy of surgeon performed US guided FNAC of thyroid nodules in the outpatient setting. Methods: This was a retrospective cross-sectional study on patients who underwent US guided FNAC followed by thyroidectomy between July 2019 and September 2022. US TI-RADS grade, FNAC Bethesda category and final histology were obtained from medical records and analysed. Result: There were 122 biopsy samples from 103 patients with a female gender preponderance of 89.3% and mean age of 46.5 years old. The majority of nodules biopsied were TI-RADS 4 and 5 (44.3% and 37.7%). Of the FNAC samples, 13.1% were non diagnostic, 27.9% benign, 14.7% atypia, 14.7% follicular neoplasm, 16.4% suspicious of malignancy and 13.1% were malignant. On final histology, adenomatoid nodules with nodular hyperplasia made up 82.5% of benign nodules and 94.9% of malignancies were papillary thyroid carcinomas (PTC). The overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 88.9%, 82.4%, 84.2%, 87.5% and 85.7% with higher accuracy rate (90.1%) when used in TI-RADS 5 nodules. Conclusion: Surgeon performed US guided FNAC for thyroid nodules is feasible and can be done in the outpatient setting thereby reducing time taken to reach a diagnosis. Standardizing techniques and use of additional modalities such as elastography may improve yield and diagnostic rates.