Clinical data: a 32-year-old woman was referred for evaluation of thyroid dysfunction. She was treated for a mild hyperthyroidism (FT4 23.5 pM/L) with daily 15 mg methimazole. 7 days after starting with thyrostatic, hypothyroid symptoms have developed (edema, sleepness, extreme fatigue). The methimazole was discontinued 17 days before present examination.

Palpation: there was a firm nodule in the ventromedial part of the right thyroid.

Functional state: euthyroidism with TSH 2.98 mIU/L, FT4 13.2 pM/L, FT3 3.95 pM/l, TSAb 0 U/L, anti-TPO 0 U/mL, anti-hTg 3 U/mL.

The lesion in question was located in the ventro-medail part of the right lobe.