I read with great interest the case report by Sun et al. (1), entitled "Papillary thyroid carcinoma treated with radiofrequency ablation in a patient with hypertrophic cardiomyopathy: a case report," which was published in the Korean Journal of Radiology (KJR), July 2016. The authors presented a subcentimetic papillary thyroid carcinoma treated by radiofrequency ablation in an inoperable condition.

In the case report, a 52-year-old woman had 9 mm sized papillary carcinoma in the right thyroid gland, which showed an intrathyroidal location with no lymph node enlargement on ultrasound. She was not a candidate for thyroid surgery owing to an underlying medical condition, so the authors chose radiofrequency ablation to treat thyroid cancer.

However, it is my opinion that simple observation for papillary microcarcinoma is more appropriate for management of thyroid cancer in such cases. Papillary microcarcinoma (measuring 10 mm or less) in the absence of other poor prognostic features such as extrathyroidal extension or lymph node metastasis runs an indolent course, so it is a good candidate for observation (23). Ito et al. (4) demonstrated a similar recurrence and mortality rate when these cancers were observed rather than treated with immediate surgery. Moreover, ablating only the primary thyroid carcinoma is not recommended because of a high incidence of multiplicity and lymph node metastasis even though the carcinoma is small in size (4). Recent American Thyroid Association guidelines do not recommend fine needle aspiration in subcentimetric thyroid nodules even with highly suspicious ultrasound patterns (2), and this trend is closely related to a "less is more" paradigm shift in the management of thyroid nodules (5).