Background: Fine needle aspiration (FNA) is a widely utilized technique for assessing thyroid nodules; however, its inherent non-diagnostic rate poses diagnostic challenges. The present study aimed to evaluate and compare the diagnostic efficacy of FNA, core needle biopsy (CNB), and their combined application in the assessment of thyroid nodules.

Methods: A total of 56 nodules from 50 patients was analyzed using both FNA and simultaneous CNB. The ultrasound characteristics were categorized according to the American College of Radiology Thyroid Imaging Reporting and Data Systems classification system. The study compared the sensitivity, specificity, and accuracy of FNA, CNB, and the combination of the two techniques.

Results: The concordance between FNA and CNB was notably high, with a kappa coefficient of 0.837. The sensitivity for detecting thyroid malignancy was found to be 25.0% for FNA, 66.7% for CNB, and 83.3% for the combined FNA/CNB approach, with corresponding specificities of 84.6%, 97.4%, and 97.4%. The accuracy of the FNA/CNB combination was the highest at 94.1%.

Conclusions: The findings of this study indicate that both CNB and the FNA/CNB combination offer greater diagnostic accuracy for thyroid malignancy compared to FNA alone, with no significant complications reported. Integrating CNB with FNA findings may enhance management strategies and treatment outcomes for patients with thyroid nodules.