Distribution patterns of metastases in recurrent laryngeal nerve lymph nodes in patients with squamous cell esophageal cancer

Esophageal cancers frequently metastasize to recurrent laryngeal nerve lymph nodes (RLNNs). Knowledge of anatomic metastatic RLNN (mRLNN) distributions is needed for lymph node dissection during esophageal cancer surgery. Among 189 patients with esophageal cancer who underwent esophagectomy between 2008 and 2010, 51 (27.0%) had mRLNN. Sixty-four mRLNNs (right, 31; left, 33) were identified via preoperative computed tomography (CT); more than 2 unilateral metastases and/or nodes with unclear boundaries were excluded. Anatomical characteristics, including vertical distance from the sternal notch level, circumferential angle to the mid-sagittal tracheal plane, and short and long axes, were measured via CT. Respective mean right and left vertical distances from the sternal notch were +2.0±13.1 mm and -14.5±23.8 mm (p=0.0006). Left mRLNNs existed in vertically wider and inferior areas along recurrent laryngeal nerve, compared to right mRLNNs. The respectivemean right and left circumferential angles around the trachea (from the anterior mid-sagittal plane) were 137.2±11.2° and 94.3±31.6° (p < 0.0001). LeftmRLNNs were distributed more widely around the trachea, especially anteriorly. The short axes were larger for right mRLNNs than for left mRLNNs (8.6 mm vs. 6.8 mm, p=0.026). Compared with the right side, left mRLNNs were smaller and had a vertically longer and circumferentially wider distribution. Careful attention should be given to the left side during curative RLNN dissection.