Predictive factors of skip metastases to lateral neck compartment leaping central neck compartment in papillary thyroid carcinoma

Summary Skip metastasis, referred to as leaping metastasis to the lateral neck without associated lymphadenopathy in the central compartment (level VI), can occur in patients with papillary thyroid carcinoma (PTC). However, there have been few studies on its predictive value in PTC patients. We reviewed the medical records of 90 patients who underwent simultaneous central and lateral neck lymph node dissection for the primary treatment of lymph node metastasis in the lateral neck of PTC patients. No patient was suspected of having metastasis in the central compartment by preoperative imaging study. The frequency of skip metastasis to the lateral neck compartment without central neck metastasis was 19% (17/90). The number of metastatic lymph nodes dissected in the lateral neck of patients with and without skip metastasis was 5.1 ± 2.7 and 9.5 ± 2.6, respectively ( P < 0.001). Skip metastasis was closely associated with significantly fewer lymphovascular invasion ( P = 0.009) and extracapsular spread ( P = 0.035). Skip metastasis can occur significantly frequently in PTC patients. The presence of lymphovascular invasion, extracapsular spread, and number of positive lymph nodes dissected were inversely correlated with skip metastasis.