Prediction and Applications of Lymph Nodes Posterior to the Right Recurrent Laryngeal Nerve Metastasis in Patients with Papillary Thyroid Carcinoma

Abstract Purpose Residues from the LN-prRLN are one of the main reasons for persistence or recurrence in patients with papillary thyroid carcinoma (PTC). However, the methods for preoperative assessment of LN-prRLN status, as well as the correlation with other clinicopathological features remains unclear. Methods Clinicopathological feature of 493 patients with PTC were retrospectively reviewed. Univariate and multivariate analyses were performed to identify the independent risk factors of LN-prRLN metastasis. The implications of positive LN-prRLN on right lateral lymph node and contralateral central lymph node metastasis were also investigated. Results Among the 493 patients, 343 (69.6%) was women and the average age was 39.06 ± 10.63 years old. Male sex, tumor size > 10 mm, extrathyroidal extension, the number of lymph nodes anterior to the right recurrent laryngeal nerve (LN-arRLN) metastasis ≥ 1, and right lateral lymph node metastasis (right-LLNM) were found as the independent risk factors of LN-prRLN metastasis in PTC. The prediction model based on those five factors performed better than the other forecast models. Moreover, positive LN-prRLN, male sex, microcalcifications, and tumor size > 10 mm significantly increases the risk of right-LLNM. Meanwhile, positive LN-prRLNand male sex will significantly increase the risk of con-CLNM. Conclusions LN-prRLN dissection should be recommended in patients with male sex, tumor size > 10 mm, extrathyroidal extension, the number of LN-arRLN metastasis ≥ 1, and present right-LLNM. Furthermore, when LN-arRLN metastasis has occurred, surgeons should be more alert to the possibility of right lateral lymph node and contralateral central lymph node metastasis.