Lobectomy for Papillary Thyroid Carcinoma With Minimal Extrathyroidal Extension: Does the Site of Extension Matter?

Abstract

There is limited data on the recurrence risk following lobectomy in patients with microscopic extrathyroidal extension (mETE) and the significance of the site of mETE. A retrospective study on patients treated with thyroid lobectomy between January 2012 and December 2023. Sixty-seven patients with papillary thyroid carcinoma (PTC) and mETE were included. Two patients (4.66%) experienced disease recurrence during a mean follow-up of 50 months (IQR 18.8-70.3). Twenty-five patients (37.3%) had anterior extension, 28 (41.8%) posterior, and 14 (20.9%) unknown location. Tumors with posterior extension had a higher rate of tall-cell variant (23.1% vs. 12%) and fewer positive surgical margins (22.2% vs. 37.5%). Three non-disease-related deaths occurred during follow-up. No recurrences were noted in patients with anterior mETE. The recurrence risk after hemithyroidectomy for PTC with mETE was 4.66%, consistent with low-risk disease. Posterior mETE demonstrated a trend of a more aggressive variant and a higher recurrence rate.