Autonomous hyperfunctioning thyroid nodules produce thyroid hormone independently of TSH. Of these, toxic thyroid nodules provoke hyperthyroidism and can be treated by surgery or radioactive iodine therapy. The aim of this study was evaluating the role of each treatment method in Korean patients with toxic thyroid nodule.

From July 2008 to June 2013, 10 patients were diagnosed with toxic thyroid nodule. We diagnosed toxic thyroid nodule by thyroid function test and thyroid scan. Thyroid function test showed hyperthyroidism. Hot nodule and suppressed uptake surrounding thyroid tissue was observed on thyroid scan. We analyzed medical records of 10 patients retrospectively.

9 patients were women and 1 patient was man. Median follow-up duration was 22 months. Most common symptom was neck mass (80%) and the median tumor size was 2.66 cm. ^99mTc uptake increased by 6.41% on thyroid scan. All 10 patients refused radioactive iodine therapy and 3 of these denied even operation. In 7 patients underwent thyroidectomy, 4 patients were proved having thyroid malignancy (3 papillary thyroid carcinomas and 1 follicular thyroid carcinoma).

In Korean patients, toxic thyroid nodule was likely to accompany thyroid malignancy and radioactive iodine therapy is contraindicated in this case. Therefore, we suggested that surgery has to be considered in the first place in treatment of toxic thyroid nodule.