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Updated: Feb 14, 2026
Transoral Robotic Total Thyroidectomy and Bilateral Central Regional Lymph Node Dissection for Papillary Thyroid Carcinoma
Published on: September 15, 2023
Small papillary thyroid carcinoma with minimal extrathyroidal extension should be managed as ATA low-risk tumor
M G Castagna1, R Forleo2, F Maino2
1Department of Medical, Surgical and Neurological Sciences, University of Siena, Siena, Italy. m.g.castagna@ao-siena.toscana.it.
Purpose:
According to American Thyroid Association (ATA) guideline, papillary thyroid cancer (PTC) with minimal extrathyroidal extension (mETE) is classified at "intermediate risk" of persistent/recurrent disease. However, the impact of mETE per se on patients' outcome is not fully understood. The aim of our study was to evaluate the prognostic significance of mETE in patients with PTC not submitted to therapeutic or prophylactic lymph node dissection, according to tumor size and other prognostic factors.
Patients And Methods:
We retrospectively evaluated a total of 514 PTC patients: 127 (24.7%) had mETE (pT3Nx) and 387 (75.3%) had negative margins (pT1-2Nx). At a median follow-up of 9.1 years, patients were divided in two groups: patients with "good outcome" (no evidence of disease) and patients with "poor outcome" (persistent structural disease or recurrent disease or tumor-related death).
Results:
The rate of patients with "poor outcome" was significantly higher in patients with mETE compared with patients with negative margins (11.8 versus 5.1%; OR 2.4576, 95% CI 1.2178-4.9594, p = 0.01). However, mETE was significantly associated with poor outcome only in patients with tumors larger than 1.5 cm.
Conclusions:
mETE is an unfavorable prognostic factor in tumors larger than 1.5 cm, suggesting that, in the absence of other unfavorable characteristics, smaller tumors with mETE should be classified and managed as "low risk" tumors.
Insights
Minimal extrathyroidal extension (mETE) in papillary thyroid cancer (PTC) is an unfavorable prognostic factor for tumors larger than 1.5 cm. Smaller PTC tumors with mETE may be managed as low-risk, despite current intermediate-risk classification.
Area of Science:
- Endocrinology
- Oncology
- Surgical Pathology
Background:
- Papillary thyroid cancer (PTC) with minimal extrathyroidal extension (mETE) is classified as intermediate risk by American Thyroid Association (ATA) guidelines.
- The independent prognostic impact of mETE on patient outcomes remains incompletely understood.
- This study investigates the prognostic significance of mETE in PTC patients without lymph node dissection.
Purpose of the Study:
- To evaluate the prognostic significance of mETE in papillary thyroid cancer (PTC) patients.
- To assess the impact of mETE on patient outcomes, considering tumor size and other prognostic factors.
- To clarify the risk stratification for PTC with mETE.
Main Methods:
- Retrospective analysis of 514 PTC patients.
- Categorization into groups based on presence (127 patients) or absence (387 patients) of mETE.
- Median follow-up of 9.1 years, classifying outcomes as 'good' (no evidence of disease) or 'poor' (persistent/recurrent disease or tumor-related death).
Main Results:
- Patients with mETE had a significantly higher rate of poor outcomes (11.8%) compared to those with negative margins (5.1%).
- mETE was significantly associated with poor outcome exclusively in patients with tumors exceeding 1.5 cm in size.
- Odds Ratio (OR) for poor outcome with mETE was 2.4576 (95% CI 1.2178-4.9594, p=0.01).
Conclusions:
- Minimal extrathyroidal extension (mETE) is an unfavorable prognostic factor in papillary thyroid cancer (PTC) tumors larger than 1.5 cm.
- Smaller PTC tumors (<1.5 cm) with mETE may warrant classification and management as low-risk, in the absence of other adverse features.
- Current risk stratification for PTC may need refinement based on tumor size and mETE.
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