Hashimoto's thyroiditis reduces central lymph node metastasis risk in papillary thyroid microcarcinoma: an integrated...

Area of Science:

• Endocrinology
• Oncology
• Surgical Pathology

Background:

• Hashimoto's thyroiditis (HT) is a frequent comorbidity in patients diagnosed with papillary thyroid microcarcinoma (PTMC).
• The necessity for prophylactic central lymph node dissection (CLND) in clinically node-negative (cN0) PTMC patients is under ongoing debate.
• This study investigates the association between concurrent HT and the risk of cervical lymph node metastasis (LNM) in PTMC.

Purpose of the Study:

• To evaluate the risk of central lymph node metastasis (CLNM) in PTMC patients with concurrent HT.
• To synthesize existing literature and conduct a case-control analysis for enhanced individualized risk assessment.
• To inform surgical decision-making for PTMC patients with or without HT.

Main Methods:

• A comprehensive meta-analysis was performed on 17 studies (11,873 cases) sourced from PubMed, Embase, and Web of Science (search up to June 2025).
• A case-control study involved a retrospective analysis of 303 consecutive PTMC patients who underwent surgery between 2017 and 2024.
• Statistical analyses included odds ratios, false-negative rates, funnel plots for publication bias, and ROC curve analysis for TPOAb cutoff points.

Main Results:

• The meta-analysis revealed HT in 26.7% of PTMC cases. The rate of positive CLNM was lower in the HT group (32.6%) versus the non-HT group (38.4%), with an odds ratio of 0.75.
• Combining ultrasonography (US) and fine-needle aspiration biopsy (FNAB) yielded a low false-negative rate of 27.5% for CLN status evaluation.
• Retrospective analysis showed a higher CLN examination rate but lower CLNM incidence in the HT group. ROC analysis identified a TPOAb cutoff of 17.9 for CLNM (sensitivity 53%, specificity 68%).

Conclusions:

• Hashimoto's thyroiditis (HT) appears to confer a protective effect, potentially reducing the risk of CLNM in PTMC patients.
• Preoperative evaluations using ultrasound and FNAB are crucial for assessing lymph node status, with TPOAb as a significant marker.
• Findings support the development of personalized management strategies for PTMC, optimizing early intervention and patient outcomes.