First examination (first row):

Clinical presentation: A 67-year-old woman was referred for evaluation of a recurrent hyperthyroidism. She was treated first 40 years ago. In the subsequent decades she had no problems with the thyroid. Three months before the present examination, complaints suggesting hyperthyroidism have evolved; including 12 kg weight loss, thyroid associated orbitopathy (TAO). Regarding the latter, the patient had conjunctivitis and exophthalmos but not diplopia.

Palpation: No abnormality.

Laboratory examination: TSH 0.001 mIU/L, FT4 53.9 pM/L.

Ultrasonography. Both lobes were hypoechogenic and inhomogeneous. There was a cystic area in the dorsal part of the right lobe. The vascularization was partly increased.

Suggestion: daily 20 mg methimazole. The patient has got large dose intravenous steroid therapy for TAO

14 months after the first visit (second row):

Clinical presentation: The thyroid functions were regularly checked in the previous year. The complaints of hyperthyroidism have resolved while the degree of exophthalmos has decreased.

Palpation: unchanged.

Laboratory examination: TSH 0.21 mIU/L, FT4 4.3 pM/L.

Ultrasonography. There were two changes in the presentation. First, the basic echo structure became less hypoechogenic. Second, the cystic area became better demarcated and a bit increased in size.

Suggestion: discontinuation of methimazole-therapy.

23 months after the first visit (third row):

Clinical presentation. The patient noticed diplopia. Otherwise, she was free of complaints.

Palpation: unchanged.

Laboratory examination: TSH 3.02 mIU/L, FT4 10.5 pM/L, TSAb 9.7 U/l (normal value < 1.5).

Ultrasonography. The thyroid became almost echonormal. The size of the cystic area remained unchanged.

The patient has got again large dose intravenous steroid therapy which had no effect. Total thyroidectomy was advised. Histopathology disclosed diffuse goiter corresponding to Graves' disease and a microfollicular adenoma corresponding to the lesion in the right lobe.

6 months after the operation the patient was free of eye complaints and she remained in this condition in the subsequent 2 years.

Comment. It is worth comparing the presentation of the cystic lesion in the first and subsequent examinations. At first time, the lesion seems to be not a pathological nodule while at the third time it seems to be a true nodule.