Incidence and predictors of right paraesophageal lymph node metastasis of N0 papillary thyroid carcinoma located in the right lobe.

Papillary thyroid carcinoma (PTC) frequently metastasizes to the regional lymph nodes and, thus, guidelines edited by Japan Association of Endocrine Surgeons/Japanese Society of Thyroid Surgery routinely recommend central node dissection even for patients with no clinically detectable node metastasis (N0). However, in the central compartment, metastasis to the right paraesophageal node has not been intensively investigated. We investigated the incidence and predictors of right paraesophageal node metastasis based on pre- and intraoperative findings in 922 patients with N0 PTC in the right lobe. Fourteen percent of patients were microscopically positive for right paraesophageal node metastasis, and the incidence was smaller than that for pre- and right paratracheal node metastasis (46%). On multivariate analysis, a tumor size ≥ 2 cm and significant extrathyroid extension were independent predictors of metastasis. Microscopically pre- and right paratracheal node-positive PTC more often (p < 0.0001) metastasized to the right paraesophageal node. Taken together, in N0 PTC in the right lobe, right paraesophageal node dissection should be considered in tumors 2 cm or larger and/or with significant extrathyroid extension, or when pre- and right paratracheal node metastasis is suspected based on the intraoperative findings.