Clinical data: A 39-year-old man came to a routine follow-up. He was operated on a recurrent hyperthyroidism of autoimmune origin 7 years ago. Histopathology disclosed diffuse goiter for more than 20 years. After surgery, 75 and 100 micrograms a day of hormone replacement were needed for years. Then, three years before the current study, hormone results suggested an overdose. He was euthyroid for a year and a half after leaving drug replacement.

Palpation: no abnormality.

Laboratory tests: TSH 0.01 mIU/L, FT3 13.8 pM/L, FT3 4.41 pM/L, TSAb 3.4 U/L (normal value below 1.5).

Ultrasonography. The thyroid lobes were composed of hypoechoic discrete areas. The vascularity of the thyroid was increased.

Suggestion: radioiodine therapy.

Comments.

1. The surgery was insufficient. The thyroid has a great capacity to regenerate. As this case proves, even the development of a hypothyroidism does not guarantee that a significant remnant will not lead to a recurrence of the hyperthyroidism.

2. This is one of the characteristic presentations of an operated thyroid, a lobe is partly hypoechoic partly echonormal. Nevertheless, this pattern is frequently misinterpreted as nodular goiter.