Papillary thyroid microcarcinomas that metastasize to lymph nodes.

Area of Science:

• Oncology
• Endocrinology
• Pathology

Background:

• Papillary thyroid microcarcinomas (PTMC) are small thyroid cancers (≤1 cm).
• Predicting lymph node metastasis (LNM) in PTMC is crucial for appropriate management.
• Clinicopathological features associated with LNM in PTMC require further elucidation.

Purpose of the Study:

• To identify clinicopathological predictors of lymph node metastasis (LNM) in papillary thyroid microcarcinomas (PTMC).

Main Methods:

• Retrospective review of medical records for 1184 PTMC patients (≤1 cm) and 872 papillary thyroid cancer (PTC >1 cm) patients.
• Comparison of demographic, clinical, and histopathological features between PTMC and PTC groups.
• Investigation of associations between clinicopathological features and LNM specifically within the PTMC cohort.

Main Results:

• Multifocality, capsular invasion, vascular invasion, and extrathyroidal extension (ETE) were more frequent in larger PTCs (>1 cm) than in PTMCs (≤1 cm).
• In PTMC patients, multifocality, capsular invasion, vascular invasion, and ETE were significantly more common in those with LNM.
• Logistic regression identified multifocality (OR 1.737) and ETE (OR 3.528) as significant predictors of LNM in PTMC. A primary tumor diameter ≥5.75 mm was also predictive.

Conclusions:

• Multifocality and extrathyroidal extension (ETE) are significant predictors of lymph node metastasis (LNM) in papillary thyroid microcarcinomas (PTMC).
• PTMC patients with a tumor diameter ≥5.75 mm, multifocality, or ETE warrant careful evaluation for LNM.