Risk factors and clinical indication of metastasis to lymph nodes posterior to right recurrent laryngeal nerve in papillary thyroid carcinoma: a single-center study in China.

BACKGROUND Lymph nodes posterior to right recurrent laryngeal nerve (PRRLN) may be frequently overlooked during central compartment dissection (CCD) for papillary thyroid carcinoma (PTC). The purpose of this study was to investigate risk factors of lymph node PRRLN metastasis in right-sided PTC, thereby to identify the indications for lymph node PRRLN dissection. METHODS We conducted a retrospective study of patients with right-sided PTC who underwent a thyroidectomy plus lymph node PRRLN dissection during ipsilateral CCD. RESULTS Overall, 108 patients (26.7%) had lymph node PRRLN metastases, including 26 (6.4%) who presented with solely lymph node PRRLN positivity. Factors of extrathyroidal extension, multifocality, larger tumor (≥1 cm), level VIa positivity (p < .0001 for each), and lateral compartments positivity (p = .0002) significantly predicted lymph node PRRLN metastasis in right-sided PTC. CONCLUSION Lymph node PRRLN should be routinely explored during CCD because of the possibility of only involvement in PTC. Factors of tumors larger than 1 cm, multifocality, and extrathyroidal extension were independent predictors of lymph node PRRLN metastasis in right-sided PTC, and suggested the clinical indications of lymph node PRRLN dissection.