Skip Metastases in Papillary Thyroid Carcinoma – Prevalence, Predictive and Clinicopathological Factors

BACKGROUND: Cervical lymph node metastases are frequently found in papillary thyroid carcinoma (PTC) and occur in a stepwise fashion. Skip metastases that omit the central compartment and spread initially in lateral neck levels are present in a certain share of patients, and their significance is poorly understood. The aim of this prospective study was to identify their possible predictors and clinicopathological factors in a group of patients with PTC with lateral lymph node (LLN) metastases. METHODS: We enrolled 68 patients with PTC with preoperatively evaluated LLN metastases who underwent total thyroidectomy with lateral lymph node dissection between 2011 and 2018. We analysed the clinicopathological features and pattern of dissemination of continuous and skip metastases. RESULTS: The prevalence of skip metastases was 23.5%. Compared with the continuous metastases group, the patients were older, had primary tumors that were more often situated unilaterally, and had smaller primary tumor size. Level II was less often involved, and none of the patients with skip metastases had all LNN positive (p = 0.05). CONCLUSION: Skip metastases occur more frequently in older patients and display certain clinicopathological features like smaller size of the primary tumor and dissemination in less lateral neck levels. In the view of the fact that they are found rather frequently, lateral neck regions should be meticulously investigated in patients with PTC without central lymph node (CLL) metastases.