Clinical presentation: a 71-year-old woman was referred for evaluation of a suspected hyperthyroidism. She had atrial fibrillation and her TSH was 0.22 mIU/L. She noticed a stable lump in the region of the right thyroid known for decades.

Palpation: a nodule in the right thyroid.

Functional state: euthyroidism with TSH 0.49 mIU/L, FT4 12.1 pM/L, FT3 4.77 pM/L, anti-TPO 0 U/mL, TRAK 0 U/L.

Ultrasonography: the thyroids were moderately hypoechogenic. There was a minimally hypoechogenic lesion lower to the right thyroid. It contained a small cystic area. The vascularization was not specific.

Cytology was performed from the lesion under the thyroid and resulted in benign colloid goiter.

The thyroglobulin-level in the wash-out of the needle was 476 ng/mL, while serum thyroglobulin was 40.3 ng/mL.

We suggested follow-up investigation. One year later the lesion did not change in size and the TSH level was 0.76 mIU/L.