Clinical presentation: A 59-year-old woman was referred for evaluation of a newly diagnosed hyperthyroidism. She was operated on Graves' disease 17 years ago. She did not require replacement therapy after surgery. Typical complaints suggesting hyperthyroidism have evolved for 3 months; these included weight loss, fatigue, elevated pulse rate and thyroid associated orbitopathy.  

Palpation: Both lobes were firm and uneven, therefore they were nodular on palpation.

Results of blood test: TSH 0.001 mIU/L, FT4 39.2 pM/L, TSAb 9.2 U/L (normal value below 1.5).

Ultrasonography: The right lobe was hypoechogenic, the left was moderately hypoechogenic. Both lobes were irregular in shape and were composed of several circumscribed areas surrounded with echonormal rim. The vascularization was significantly increased.

Daily 20 mg methimazole therapy was started. Considering the severe thyroid associated orbitopathy including diplopia, surgery was advised.

Total thyroidectomy was performed. Histopathology disclosed diffuse goiter corresponding to Graves' disease. No nodules were found.

Comments.

1. An experienced thyroidologist is not very happy if a patient is euthyroid without replacement therapy after surgery. The thyroid has a great capacity to recover and therefore a patient who is euthyroid years after an operation performed because of Graves' disease shares a relatively high risk to develop recurrent hyperthyroidism even decades after surgery.

2. The sonographic pattern is specific. At first sight both lobes, particularly the right one seems to be nodular. First, the lobes are composed of a central hypoechogenic part surrounded with an echonormal rim, therefore it seems like the lobes were composed of a large hypoechogenic nodule. Second, connective tissue, perhaps a scar makes an impression in the ventral and in the dorsal part of the right and the left lobe, respectively. This makes an appearance as the lobes were composed of two nodules or one lesion with irregular lobulated and spiculated margins. In fact, the scar is responsible for the irregularities seen on the surface of the hypoechogenic mass, and regarding the hypoechogenic mass, the inclinations are the primary cause.