Active Surveillance for Low-risk Papillary Thyroid Microcarcinoma

AS was performed in patients who were diagnosed with low-risk PTMC and chose this management, as described previously.^{7 (link),19 (link),20 (link)} Our AS of clinically low-risk PTMC was a management plan for performing CS at an appropriate time in cases of disease progression. In brief, we asked patients to visit our clinic periodically to evaluate tumor status and nodal status on ultrasonography. We regarded tumors as enlarged when the maximal diameter increased by ≥3 mm compared with the initial size. We discussed CS with the patients, and if the patients preferred to pursue AS, we continued AS until the tumor size reached 13 mm. If lymph node metastasis was suspected, we performed cytological examination of the node with thyroglobulin measurement of the needle washout. We recommended CS if a nodal metastasis was diagnosed.