Clinical presentation: A 31-year-old woman presented with a relapse of hyperthyroidism 2 months after discontinuation of thyrostatic therapy. Propylthiouracil treatment was restarted 6 weeks prior to the present examination.

Palpation. No abnormality.

Laboratory tests: TSH 0.01 mIU/L, FT4 9.03 pM/L, FT3 3.96 pM/L on daily 30 mg propylthiouracil.

Ultrasonography. The thyroid was echonormal and contained several hypoechogenic areas. The vascularization was average.

We suggested radioiodine therapy but the patient chose instead to undergo on surgery.

Total thyroidectomy was performed. Histopathology disclosed diffuse goiter and chronic lymphocytic thyroiditis.