Lymph node dissection in the lateral neck for completion in central node-positive papillary thyroid cancer

BackgroundIn papillary thyroid cancer, quantitative relationships may exist between central and lateral neck lymph node metastases, which may be of clinical usefulness.MethodsThis comparative analysis of central and lateral neck lymph node metastases was undertaken in 88 patients with untreated papillary thyroid cancer who underwent compartment-oriented lymph node dissection in the central and ipsilateral lateral neck. In 32 of these patients, the contralateral lateral neck was dissected in addition.ResultsCentral lymph node metastases were categorized in increments of 0 (22 patients), 1–5 (29 patients), 6–10 (12 patients), and more than 10 positive nodes (25 patients). With more than 5 positive nodes, the rates and numbers of lateral lymph node metastases increased from between 45% and 69% to 100% and from a mean of between 2 and 3 to between 6 and 8 lymph node metastases (all P < .001) in the ipsilateral neck; and from between 0% and 33% to between 60% and 71% (P = .009) and from a mean of between 0 and 1 to between 3 and 7 lymph node metastases (P = .003) in the contralateral neck. Lateral lymph node metastases in the contralateral neck always coexisted with metastases in both the central and the opposite lateral neck. When only patients with positive lateral nodes were considered, the successive increase in the number of lateral lymph node metastases was still present. Altogether, the ipsilateral neck harbored more often lateral lymph node metastasis with more positive lateral nodes than the contralateral neck.ConclusionThese histopathologic associations may provide a foundation for more evidence-based decisions regarding lymph node dissection of the lateral neck compartments in patients with node-positive papillary thyroid cancer.