The value of thyroglobulin measurement in fine-needle aspiration for diagnosis of suspicious lymph nodes in patients with thyroid carcinoma after thyroidectomy

Abstract

To investigate the value of thyroglobulin measurement in ultrasound guided fine-needle aspiration(FNA-Tg)for detecting neck node metastasis in patients with papillary thyroid carcinoma(PTC)after thyroidectomy. A total of 128 suspicious metastatic lymph nodes in 112 patients were retrospectively analyzed. Postoperative pathologic results were taken as the gold standard. The values of FNA and FNA-Tg combined FNA in the diagnosis of metastatic lymph nodes were compared with different ultrasonic features. The sensitivity, specificity and accuracy of single FNA for the diagnosis of neck node metastasis were 67.5%, 98.0% and 79.7% respectively, and those of FNA-Tg combined FNA were 87.0%, 100.0% and 92.2% respectively. Compared with single FNA, the sensitivity and accuracy of FNA-Tg combined FNA were increased significantly(χ(2)=8.319, P=0.004; χ(2)=8.275, P=0.004). When the ultrasonographic characteristics met any one of five indicators for neck node metastasis, the sensitivity, specificity and accuracy of single FNA for the diagnosis of neck node metastasis were 38.1%, 95.7% and 68.2% respectively, and those of FNA-Tg combined FNA were 71.0%, 100.0% and 86.4% respectively. Compared with single FNA, the sensitivity and accuracy of FNA-Tg combined FNA were increased significantly(χ(2)=4.709, P=0.030; χ(2)=4.141, P=0.042). When the ultrasonographic characteristics met any two of five indicators for neck node metastasis, the sensitivity, specificity and accuracy of single FNA for the diagnosis of neck node metastasis were 55.0%, 100.0% and 73.5% respectively, and those of FNA-Tg combined FNA were 90.0%, 100.0% and 94.1% respectively. Compared with single FNA, the sensitivity and accuracy of FNA-Tg combined FNA were increased significantly(χ(2)=6.140, P=0.013; χ(2)=5.314, P=0.021). The ultrasonographic characteristics met any three, four or five of five indicators or did not meet any of the indicators, there was no significant difference in the value of the diagnosis of metastatic lymph nodes between single FNA and FNA-Tg combined FNA(P>0.05). The combination of FNA with FNA-Tg could be helpful in diagnosis of lymph node metastasis. When the suspicious lymph nodes had one or two ultrasound characteristics for neck node metastasis, FNA-Tg could raise the sensitivity and accuracy of FNA, and FNA-Tg could not significantly improve in the diagnosis of FNA when presenting with no or with more than 2 ultrasonographic features.