Background Papillary thyroid carcinoma (PTC) is the most common pathological type of thyroid carcinoma. We aim to evaluate the association of sonographic features of PTC and cervical lymph node metastasis (CLNM) at the initial surgery. Methods Clinical information, ultrasonographic measurements and features for 1335 patients were acquired in data collection. Univariate analysis was performed to test CLNM by 7 independent variables. Receiver operating characteristic (ROC) curve was created to

more »

... luate the diagnostic performance. Results Univariate analysis showed that gland, location, aspect ratio, margin and echogenic foci were independently associated with CLNM metastatic status (P<0.05). Binary linear regression analysis showed that sex, age, tumour maximum diameter and volume, location, margin and echogenic foci were independent correlative factors. The ROC curves were established based on the relevant factors, the AUC of tumour maximum diameter, tumour volume and margin were 0.74, 0.73, and 0.71, respectively. The multiple-variable linear regression model was constructed with AUC of 0.81, specificity of 72.8%, and sensitivity of 75.0%. ANOVA variance analysis for sub-positive groups, tumour maximum diameter, tumour volume, margin and echogenic foci had statistical significance (P<0.05).Conclusion Younger age, male, larger tumour, margin, and echogenic foci were high risk factors for CLNM in PTC. Cross-sectional aspect ratio with value≥1 had higher predictive value for CLNM in patients with larger thyroid tumors.