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

Abstract

SUMMARY 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.

Analysis of factors influencing cervical lymph node metastasis of papillary thyroid carcinoma at each lateral level

“…Skip metastasis occurs when tumor cells bypass the CLNs, and metastasis first occurs in the LLNs. This phenomenon has been reported in several studies, affecting approximately 21.8–23.5% of patients [ 6 , 7 ]. In this study, 13 of 203 patients with lateral metastasis had skip metastasis.…”

Related factor analysis for predicting large-volume central cervical lymph node metastasis in papillary thyroid carcinoma

“…It is generally accepted that tumor cells spread in a stepwise way: from central to lateral neck regions. Skip metastases that omit the central compartment and spread initially in lateral neck levels only occur in a small number of patients ( 8 ). In addition, researchers confirmed that large-volume CCLNM was an independent risk factor of lateral LNM in PTC ( 9 ).…”

Predictive Factors Affecting the Development of Lateral Lymph Node Metastasis in Papillary Thyroid Cancer

“…In the present study, the rate of clinical lateral metastasis in patients was 10%, and in the literature, the prevalence of LLNM in patients with PTC ranged from 6.5% to 27.5%. [ 5 , 6 ] In the literature, the male sex ratio is reported to be higher in patients with LLNM. [ 6 ] In a comprehensive meta-analysis, including 18741 patients of 23 studies, by So et al, [ 23 ] male gender is found to be an effective factor in the development of LLNM.…”

“…Lymphovascular invasion is considered another risk factor for the development of LLNM. [ 5 ] In the study of Lombardi et al, [ 31 ] the number of skip lateral metastases without metastases in the central compartments was reported to be significantly higher in patients with lymphovascular invasion. In another meta-analysis including 23 studies and 18741 patients evaluating LLNM in PTC; lymphovascular invasion was determined as a significant risk factor for the development of LLNM.…”

“…[2][3][4] In the literature, the prevalence of lateral lymph node metastasis (LLNM) in patients with PTC ranged from 6.5% to 27.5%. [5,6] PTC patients with LLNM have a higher incidence of disease recurrence and distant metastases than PTC patients with or without central lymph node metastasis (CLNM). [7] Therefore, an adequate assessment of the lateral lymph node status before surgery is very important in determining the surgical strategy and predicting the patient's survival.…”