[Association between thyroid nodule diameter measured by ultrasound and thyroid papillocarcinoma]

Objective: To investigate the association between thyroid nodule diameter measured by ultrasound and thyroid papillocarcinoma. Methods: A total of 389 cases undergoing thyroidectomy because of thyroid nodule between January 2016 and June 2017 in Beijing Anzhen Hospital were retrospectively reviewed. Of these patients, 170 cases had thyroid papillocarcinoma, and 219 cases had benign nodule. The nodules were divided into five groups according to their diameters: ≤1.0 cm, 1.1-2.0 cm, 2.1-3.0 cm, 3.1-4.0 cm, >4.0 cm. The prevalence of papillocarcinoma and lymphatic metastasis in each group were compared. Results: There were significant differences in age [(45.4±12.8) years vs (51.7±13.4) years, P<0.001], thyroid stimulating hormone (TSH) [1.75(1.28, 2.65) mU/L vs 1.48(0.99, 2.23) mU/L, P=0.003], thyroid-peroxidase antibody (TPOAb) [1.65(0.60, 8.40) kU/L vs 0.90(0.50, 2.40) kU/L, P=0.001], and C-reactive protein (CRP)[0.60(0.31, 1.37) mg/L vs 0.85(0.42, 1.66) mg/L, P=0.023] between thyroid papillocarcinoma and benign nodule. Of those(≤1.0 cm, 1.1-2.0 cm, 2.1-3.0 cm, 3.1-4.0 cm, >4.0 cm) five groups, the prevalence of papillocarcinoma was 72.5%, 52.5%, 29.7%, 16.1%, 2.4%, respectively(P<0.05). For papillocarcinoma patients, in diameter ≤1.0 cm and >1.0 cm groups, the prevalence of lymphatic metastasis was 29.9% and 45.8%, respectively (P=0.032). Binary logistic regression analysis showed that TSH (OR=1.350, 95%CI: 1.057-1.660, P=0.009), age(OR=0.960, 95%CI: 0.937-0.983, P=0.001) and nodule diameter (OR=0.359, 95%CI: 0.269-0.480, P=0.001) were independent associated factors of papillocarcinoma. Conclusion: As nodule diameter increased, the proportion of papillocarcinoma decreased, while the risk of lymphatic metastasis increased.