ObjectiveTo investigate the role of intraoperative frozen section pathology in central lymph node metastasis of papillary thyroid microcarcinoma (PTMC), and to analyze the risk factors of central lymph node metastasis.MethodsClinical data of 481 patients diagnosed with PTMC from January 2015 to June 2019 in our hospital were included. The consistency of frozen pathological results of intraoperative prelaryngeal lymph nodes, pretracheal lymph nodes, and paratracheal lymph nodes with postoperative paraffin pathological results, as well as the relationship between the numbers of intraoperative lymph nodes sent for examination and postoperative pathological results were analyzed. Then the Kappa value were calculated respectively. Furthermore, univariate and multivariate analysis were used to analyze the factors affecting central lymph node metastasis.ResultsCentral lymph node metastasis was found in 207 patients with PTMC (43.0%). Of the 207 patients, 192 patients were examined by frozen section, with 139 patients had positive results. The Kappa value of prelaryngeal lymph nodes, paratracheal lymph nodes, pretracheal lymph nodes, and central lymph nodes were 0.300, 0.643, 0.560, and 0.755, respectively (P<0.001). Simultaneous intraoperative examination of three anatomic lymph nodes in the central region has a high accuracy in evaluating whether there was lymph node metastasis. The consistency test between intraoperative frozen and postoperative paraffin pathological results showed that when the number of lymph nodes was less than 5, the Kappa value was 0.690 (P<0.001), and when more than or equal to 5, the Kappa value was 0.816 (P<0.001). The results of logistic regression showed that, maximum value of tumor diameter, tumor number, and thyroid capsule involvement were risk factors for central region lymph node metastasis in PTMC (P<0.05).ConclusionsCentral region lymph node metastasis in PTMC was common. Prelaryngeal lymph nodes, pretracheal lymph nodes, and paratracheal lymph nodes should be selected for frozen pathological examination during the operation, which could effectively indicate whether the central lymph nodes were involved. And combined with the risk factors of lymph node metastasis, such as maximum value of tumor diameter, number of tumors, and thyroid capsule involvement, a more accurate individualized operation plan can be designed for patients.