Abstract: Objective  To analyze the ultrasonographic features of papillary thyroid Microcarcinoma (PTMC) and to evaluate its clinical diagnostic value for PTMC. Methods  A retrospective study of 203 patients with thyroid nodules ≤1 cm confirmed by ultrasonography and surgical pathology was established in our hospital from January 2015 to September 2018, including 103 cases of PTMC and 100 cases of benign thyroid nodules. The sonographic differences of benign and malignant thyroid nodules were analyzed. According to the pathological results, the receivers' operating characteristic  curve (ROC) and the area under curve (AUC) were used to evaluate the diagnostic efficacy of ultrasound on PTMC. Results  Nodular echo, cystic solidity, microcalcification, aspect ratio, border, margin, and acoustic halos were significantly different between PTMC and benign thyroid nodules (P<0.05). Ultrasonography showed good diagnostic value for PTMC with an AUC of  0.88（95%CI: 0.840.93）. When TI RADS4 was used as the cutting point, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of ultrasound for PTMC diagnosis were 85.4%, 75.0%, 80.2%, 77.8% and 83.3%, respectively. Conclusion  PTMC has characteristic features on sonograms. Ultrasonography has a good clinical diagnostic value for PTMC.

Key words: thyroid neoplasms, papillary thyroid carcinoma, ultrasonography