Active Surveillance May Be the Best Initial Management for Papillary Thyroid Microcarcinoma.

Active surveillance for low-risk papillary thyroid microcarcinoma (PTMC; T1aN0MI) was initiated at Kuma Hospital (Kobe, Japan) in 1993, based on a proposal by Akira Miyauchi. Favorable outcomes of such surveillance have been reported. Our latest study revealed 5- and 10-year tumor enlargement rates (by ≥ 3 mm) of 3.0% and 5.5% and 5- and 10-year node metastasis appearance rates of 0.9% and 1.1%, respectively. The postoperative prognosis did not differ between patients who underwent immediate surgery and those who underwent conversion surgery after progression. These findings suggest that active surveillance may be the best initial management of PTMCs.