The combination of ATA classification and FNA results can improve the diagnostic efficiency of malignant thyroid nodules

Purpose: To determine the diagnostic efficiency of the ATA classification and ultrasound-guided fine-needle aspiration (FNA) results in identifying the risk factors of malignancy, we analyzed the thyroid nodules of patients who underwent thyroidectomy and compared preoperative ATA classifications with FNA results. Methods: We retrospectively analyzed 274 nodules of 196 patients who underwent ultrasonography, FNA and thyroidectomy. Histopathological findings of thyroid nodules were considered as the Au standard in the analysis of the diagnostic efficiency of the ATA classification and FNA results. Univariate analysis and binary multivariate logistic regression analysis were applied to identify the ultrasound features associated with malignancy. Results: The overall malignancy rate of 274 nodules was 41.6%. The areas under the ROC curves (AUCs) for the ATA classification and FNA results were 0.88 and 0.878, respectively (P < 0.001). The sensitivity and specificity of the ATA classification were 86 and 86.9%, whereas those of FNA results were 68.5 and 91.4%, respectively. The specificity (98.7%) and sensitivity (94.3%) increased after the combined use of the ATA classification and FNA results. Taller-than-wide shape, microcalcifications, hypoechogenicity and irregular margins were independent risk factors for malignancy. Microcalcifications had the highest OR (7.58), and taller-than-wide shape had the highest specificity in BSRTC I, II, III and IV cytology. Conclusion: The diagnostic efficiency of the ATA classification and FNA results in identifying malignant nodules was high, and the use of both criteria improved the diagnostic accuracy. Taller-than-wide shape, microcalcifications, hypoechogenicity and irregular margins were independent risk factors for malignancy.