Clinical data: a 47-year-old man was referred for evaluation of hyperthyroidism and neck complaints, i.e. he felt pressure in recumbent position for a months.

Palpation: an elastic nodule in the left thyroid.

Functional state: hyperthyroidism (TSH 0.01 mIU/L, FT4 29.1 pM/L).

Ultrasonography. The thyroid was echonormal. The right lobe contained two nodules, a cystic lesion and a moderately hypoechogenic one presenting ambiguous hyperechogenic figures. There was a large mixed nodule in the left lobe.

Cytology was performed from two nodules. In the event of the right, moderately hypoechogenic lesion FNAC resulted in benign, colloid goiter. We aspirated 9 mL brown fluid from the left nodule and only blood cells and macrophages were on this smear.

Scintigraphy disclosed an autonomous functioning adenoma in the left lobe.

Daily 15 mg methimazole was administered. 5 weeks later the FT4 level has normalized. We offered radioiodine therapy but the patient wished to avoid this resolution and underwent on left lobectomy and near total right lobectomy.

Histopathology: follicular adenoma with regressive changes in the left lobe and hyperplastic nodules in the right thyroid.