Clinical presentation: A 45-year-old woman was referred for a preoperative ultrasound examination. She has been treated for recurrent hyperthyroidism for more than a decade.

Palpation. Both lobes were firm and enlarged.

Laboratory tests: TSH 9.72 mIU/L, FT4 7.08 pM/L on daily 20 mg propylthiouracil.

Ultrasonography. The thyroid was hypoechogenic and presented both echogenic granules and lines which corresponded to connective tissue.

Total thyroidectomy was performed. Histopathology disclosed diffuse goiter.