Objective To investigate the risk factors of cervical lymph node metastasis in single papillary thyroid microcarcinoma (PTMC).

Methods The relationship between ultrasound features of cancer nodule and cervical lymph node metastasis in patients with single PTMC confirmed by surgery and pathology was analyzed retrospectively, and the risk factors for cervical lymph node metastasis in PTMC were analyzed.

Results Among the 119 PTMC patients, 86 cases (72.3%) had no cervical lymph node metastasis, and 33 cases (27.7%) had cervical lymph node metastasis. The proportion of males in the observation group was higher than that in the control group (P<0.05), and the age in the observation group was significantly lower than that in the control group (P<0.01). In the ultrasound features of PTMC nodules, there were statistically significant differences in the maximum diameter of cancer nodule, abundant blood flow, and breakthrough of capsule between the two groups (P<0.01). Logistic regression analysis showed that age, maximum diameter of cancer nodule, and breakthrough of capsule were risk factors for cervical lymph node metastasis in PTMC (P<0.01). ROC curve analysis showed that the diagnostic cut-off value of age for predicting cervical lymph node metastasis in PTMC was 43.5 years old, the area under the ROC curve was 0.769 (95%CI: 0.669-0.869), the sensitivity was 66.7%, and the specificity was 80.2%;the diagnostic cut-off value of maximum diameter of cancer nodule for predicting cervical lymph node metastasis in PTMC was 6.5 mm, the area under the ROC curve was 0.801 (95%CI: 0.719-0.882), the sensitivity was 81.8%, and the specificity was 66.3%.

Conclusions There is a certain correlation between the age, some ultrasound features and cervical lymph node metastasis in PTMC patients, which may provide some references for the clinical treatment of PTMC.