Clinical presentation: A 46-year-old woman was referred for follow-up examination. She has been treated for recurrent hyperthyroidism for more than five years. The last relapse occurred 3 months ago.

Palpation. No abnormality.

Laboratory tests: TSH 0.03 mIU/L, FT4 10.4 pM/L, FT3 5.26 pM/L on daily 10 mg methimazole.

Ultrasonography. The thyroid was echonormal and contained multiple hypoechogenic areas. The echogenicity index was around 50%. No discrete lesion fit to a nodule in a pathological sense. The vascularization was a bit increased.

We suggested radioiodine therapy, but the patient refused our suggestion because in her sister treated with radioiodine several years ago, a severe thyroid associated ophthalmopathy had developed after the therapy.

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