Risk factors and the preoperative assessment of right para-oesophageal lymph node metastasis in right lobe papillary thyroid carcinoma: A case series

Background: Right para-oesophageal lymph nodes (RPELN) are included among the right central compartment lymph nodes (rCLN) and located behind right recurrent laryngeal nerve (rRLN). However, due to the likelihood of increasing postoperative complications, and the extremely difficulties of RPELN dissection, the decision to perform RPELN dissection remains controversial. The aim of this study was to explore the risk factors of RPELN metastasis and evaluate RPELN metastasis by preoperative examination.

Methods: We reviewed the medical records of 163 consecutive papillary thyroid carcinoma (PTC) patients (125 females and 38 males) who underwent right lobe plus isthmic resection (91 patients) or total thyroidectomy (72 patients) with right or bilateral central compartment lymph node dissection. The RPELN dissections were performed in all patients and were individually dissected and recorded intraoperatively. All patients underwent thyroid ultrasound and enhanced neck computed tomography (CT) routinely during preoperative examination.

Results: RPELN metastasis was detected in 20 patients (12.3%), among whom 6 (3.7%) had RPELN metastasis without rCLN metastasis. Total rCLN metastasis and lateral compartment lymph node metastasis were confirmed in 57 (35.0%) and 24 (14.7%) patients, respectively. The tumour diameter, number of metastatic rCLN and lateral compartment lymph nodes, RPELN visible on CT, and enhanced CT value of RPELN were confirmed significantly associated with RPELN metastasis by univariate analysis (P < 0.05). The area under the ROC curve of CT values was 0.77 (95% CI, 0.59-0.95; P = 0.003). The CT value of 132.0 was used as the cut-off point, and the specificity and sensitivity were 84.1% and 71.4%, respectively.

Conclusions: PTC patients with a large tumour (>1 cm) in the right lobe or suspected rCLN metastasis were recommended to undergo prophylactic RPELN dissection, particularly in those with a high enhanced CT value (>132) of RPELN or those with the copresence of lateral compartment lymph node metastasis.