Introduction: Certain surgeon-performed ultrasound (SUS) features may predict differentiated thyroid cancer (DTC). The purpose of this study was to determine the SUS characteristics that are strongly associated with DTC in patients with solitary thyroid nodules.
Methods: A retrospective review of 115 patients with solitary thyroid nodules who had SUS before thyroid surgery was performed. Patients were subdivided into two groups based on final pathology results: patients with DTC(n=61) and those with benign disease (BD) (n=54). SUS characteristics of thyroid nodules were studied, including size, type, calcifications, borders, shape, and echogenicity. For SUS features, odds ratio (OR), confidence interval (CI), and P values are presented.
Results: Of 115 operated patients with solitary thyroid nodules, 53% (61/115) had DTC [papillary, 59%; follicular variant/papillary, 34%; Hürthle cell, 5%; and follicular, 2%] and 47% (54/115) had BD [hyperplastic, 56%; follicular adenoma, 31%; lymphocytic thyroiditis, 7%; and Hürthle cell adenoma, 6%]. Univariate analysis showed that hypoechogenicity, irregular borders, and microcalcifications were associated with an increased risk for DTC compared to hyper/isoechogenicity, regular borders, and coarse/no calcifications. Association strength was confirmed using a multivariate model, including the five SUS characteristics. Hypoechogenicity (OR=4.27; 95% CI, 1.74-10.47; P<0.002), irregular borders (OR=3.10; 95% CI, 1.25-7.7; P<0.015), and microcalcifications (OR=2.65; 95%CI, 1.04-6.76; P<0.05) had a greater association with DTC after adjustment for the other four SUS features. Additionally, the combination of hypoechogenicity, irregular borders, and microcalcifications had the strongest association with DTC (OR=30.1; 95% CI, 7.76-119.2; P<0.0001).
Conclusions: Hypoechogenicity, irregular borders, and microcalcifications were most strongly associated with an increased risk for DTC. These SUS characteristics may have additional clinical value in predicting DTC in patients with solitary thyroid nodules.