The Application of Ultrasound and Fine-Needle Aspiration in Low-Volume Lateral Lymph Nodes of Papillary Thyroid Carcinoma Patients.

This research investigates the application of high-frequency ultrasound (US) examination and US-guided fine-needle aspiration (US-FNA) in diagnosing low-volume metastatic lateral lymph nodes (LLNs) from papillary thyroid carcinoma patients. This study reviewed the medical records of 996 LLNs from 858 patients with suspicious thyroid nodules or after thyroidectomy from January 2013 to January 2016. All patients took US-FNA. The US characteristics and the malignancy rate of LLNs classified into group A and group B based on size were analyzed and compared (group A, ≥6 mm; group B, <6 mm). Size was not an independent predictor for malignancy (P > 0.005) in multiple regression analysis, whereas the malignancy rate in the large LLNs (286/425; 67.3%) was slightly higher than that in the small LLNs (338/571; 59.2%) (P = 0.01). However, no significant difference was observed between the groups in terms of calcification, absence of hilum, and peripheral vascularization. The prevalence of malignant LLNs was slightly higher in the small LLNs than that in the large ones when there were less than 3 suspicious US features (P < 0.05), and there was no significant difference between the small and large LLNs when there were 3 or more suspicious US features (P > 0.05). The results indicate that metastases may occur in the lymph nodes even when they were small. Ultrasound and US-FNA showed excellent performance in the diagnosis of low-volume metastatic lateral lymph nodes from papillary thyroid carcinoma patients.