Value of ultrasound in evaluating metastatic lymph nodes in patients with papillary thyroid carcinoma

Objective To evaluate the value of ultrasound in diagnosing metastatic lymph nodes of different cervical compartments in patients with papillary thyroid carcinoma. Methods A total of 316 suspicious cervical lymph nodes from 213 papillary thyroid carcinoma patients diagnosed preoperatively by ultrasonography were evaluated in this study. The lymph nodes were divided into either a benign or malignant group according to pathology, and divided into either a central neck region group or a lateral neck region group according to the location of lymph nodes. The diagnostic efficacy of ultrasound and ultrasound features of cervical lymph nodes from different compartments were analyzed by the χ2 test and Fisher exact test. Results All the 213 patients underwent central lymph node dissection, alone or combined with lateral neck dissection. Among the 161 central lymph nodes, 102 (63.35%) were diagnosed as metastatic lymph nodes. Of 155 lateral neck lymph nodes, 112 (72.26%) were malignant. There were significant differences in ultrasound features including size, shape, internal echo, vascularity, and the presence of inner solid content or calcification between central and lateral neck lymph nodes (Z=7.596; χ2=36.43, 10.59, 8.89, 45.85, 11.13, 51.55; all P<0.05). The ultrasound characteristics of absence of echogenic hilum and hyperechogenicity in lateral lymph nodes indicated metastatic lymph nodes (χ2=18.559, P<0.05), but no ultrasound finding could predict metastatic lymph nodes in the central region. Conclusion Traditional ultrasonography features are insufficient in diagnosing metastatic lymph nodes in the central region, and the performance of ultrasound is lower in evaluation of central lymph nodes than lateral ones. Key words: Ultrasonography; Thyroid carcinoma; Lymph node