Level IIb neck dissection guided by fine-needle aspiration for N1b papillary thyroid carcinoma

The extent of neck dissection for patients with papillary thyroid carcinoma (PTC) metastasis in lateral cervical lymph nodes is still debated. Studies aiming to omit level IIb were generally based on postoperative histopathologic information. The purpose of this study was to evaluate the predictive value of fine-needle aspiration (FNA) for level II lymph nodes in identifying candidates for neck dissection sparing level IIb before surgery.

We prospectively enrolled 156 consecutive previously untreated PTC patients with lateral neck metastases who were subjected to 178 therapeutic lateral neck dissections (including level IIa, IIb, III, IV, and Vb) between June 2018 and August 2021. Ultrasound-guided FNA of suspicious lymph nodes at level II was preoperatively performed. The cytology of FNA and thyroglobulin (Tg) washout concentration with other clinical predictors was analyzed for lymph node metastases at level IIb.

Preoperative ultrasonography revealed suspicious lymph nodes at level II in 118 cases, and fifty were positive on FNA results. Metastasis at level IIb was seen in 17 (9.6%) of the postoperative specimens. By univariate analysis, the rate of level IIb metastasis was significantly higher in patients with FNA-positive lymph nodes at level II (P<0.001, odds ratio = 16.899). The tumor sizes of the two FNA-negative level IIb metastatic lymph nodes were 0.4 mm and 3 mm.

Level IIb lymph node dissection may be omitted in the treatment of N1b PTC patients if FNA to level II lymph nodes is negative.