Ultrasound‐guided needle biopsy of large thyroid nodules: Core needle biopsy yields more reliable results than fine needle aspiration

PURPOSE: The objective of this study was to compare the false negative rate, sensitivity and false positive rate of ultrasound (US)-guided fine needle aspiration (FNA) with those of US-guided core needle biopsy (CNB) for large thyroid nodules ≥2.0 cm, which reportedly have an increased risk of thyroid malignancy. METHODS: We retrospectively studied surgically confirmed thyroid nodules that had preoperative US-guided FNA or CNB between March 2005 and December 2013. We reviewed nodule size, sonographic features, cytohistologic results, and final surgical pathology. We assessed false negative rates, sensitivity, and false positive rates by biopsy method and nodule size for diagnosis of thyroid malignancy. We assessed complications for procedures. RESULTS: US-guided CNB showed better diagnostic performance, in terms of lower false negative rates and greater sensitivity, than US-guided FNA in large thyroid nodules. There was no significant difference in false positive rate according to biopsy methods in large thyroid nodules. The false negative rates of large thyroid nodules (≥2.0 cm) were higher than those of small nodules (<2.0 cm). There were no major complications, and no significant differences in complication according to biopsy methods. CONCLUSION: US-guided CNB improved the false negative rate and sensitivity for large nodules. Therefore, US-guided CNB can be considered a useful diagnostic method for large thyroid nodules that might reduce the risk of unnecessary diagnostic surgery.