The clinical significance of the right para-oesophageal lymph nodes in papillary thyroid cancer

Purpose: Although guidelines indicate that routine dissection of the central lymph nodes in patients with thyroid carcinoma should include the right para-oesophageal lymph nodes (RPELNs), located between the right recurrent laryngeal nerve and the cervical oesophagus and posterior to the former, RPELN dissection is often omitted due to high risk of injuries to the recurrent laryngeal nerve and the right inferior parathyroid gland. Materials and Methods: We retrospectively identified all patients diagnosed with papillary thyroid carcinoma who underwent total thyroidectomy with central lymph node dissection, including the RPELNs, between January 1, 2009 and December 31, 2013 at the Thyroid Cancer Center of Yonsei University College of Medicine, Seoul, Korea. Results: Of 5556 patients, 148 were positive for RPELN metastasis; of the latter, 91 had primary tumours greater than 1 cm (p<0.001). Extrathyroidal extension by the primary tumour (81.8%; p<0.001), bilaterality, and multifocality were more common in patients with than without RPELN metastasis; however, there were no significant differences in age and sex between groups. A total of 95.9% of patients with RPELN metastasis had central node (except right para-oesophageal lymph node) metastasis, and the incidence of lateral neck node metastasis was significantly higher in patients with than without RPELN metastasis (63.5% vs. 14.3%, p<0.001). Forty-one patients underwent mediastinal dissection, with 11 patients confirmed as having mediastinal lymph node metastasis with RPELN metastasis on pathological examination. Conclusion: RPELN metastasis is significantly associated with lateral neck and mediastinal lymph node metastasis.