Superior Located Papillary Thyroid Microcarcinoma is a Risk Factor for Lateral Lymph Node Metastasis

Area of Science:

• Endocrinology
• Oncology
• Surgical Pathology

Background:

• Identifying prognostic factors for lateral lymph node metastasis (LLNM) in papillary thyroid microcarcinoma (PTMC) is crucial for determining surgical extent.
• Previous studies on LLNM predictors in PTMC were limited by sample size (under 1000 cases) and lacked focus on tumor location-specific risks.
• This study represents the largest investigation, analyzing 2967 PTMC patients to identify LLNM predictors, with a specific emphasis on lesion location.

Purpose of the Study:

• To identify predictive factors for lateral lymph node metastasis (LLNM) in papillary thyroid microcarcinoma (PTMC).
• To specifically investigate the impact of tumor location, particularly in the superior pole, on LLNM and recurrence.
• To provide data for improved preoperative evaluation and postoperative follow-up strategies in PTMC management.

Main Methods:

• Retrospective review of 2967 PTMC patients who underwent total thyroidectomy and neck dissection (January 1997 - June 2015).
• Multivariate analysis to identify significant predictors of LLNM and locoregional recurrence (LRR).
• Propensity score matching analysis was performed to account for selection bias related to tumor location.

Main Results:

• Superior lesion location, male gender, age under 45, and central lymph node metastasis (CLNM) were significant predictors of high-risk LLNM.
• Superior lesion location and CLNM were significant risk factors for LRR.
• After propensity score matching, superior lesion location, age under 45, and CLNM remained independent predictive factors for LLNM and LRR.

Conclusions:

• Superiorly located PTMC is a significant risk factor for LLNM and LRR.
• Meticulous assessment for LLNM is required in PTMC patients with superior pole lesions.
• Findings emphasize the importance of lesion location in preoperative evaluation and postoperative follow-up for PTMC.