Clinical presentation: A 38-year-old woman was referred for evaluation of a newly detected hyperthyroidism.

Palpation. Both lobes were enlarged.

Laboratory tests: TSH 0.001 mIU/L, FT4 > 75 pM/L.

Ultrasonography. The thyroid was deeply hypoechogenic and presented proliferation of connective tissue. There were no discrete lesions. The vascularization was extremely increased.

The patient was treated with methimazole. Four months later she underwent total thyroidectomy because the size of the thyroid practically excluded a long-lasting remission.

Histopathology: Diffuse goiter corresponding to Graves' diseases. Focal lymphocytic thyroiditis.