First examination (1st and 2nd rows of images):

Clinical presentation: a 57-year-old woman was referred for an evaluation of typical complaints suggesting hypothyroidism. A hypoechogenic nodule was described in the dorsal part of the right thyroid on a previous ultrasound.

Palpation: enlarged, firm thyroids without any palpable nodule.

Functional state: hypothyroidism with TSH 41.9 mIU/L, FT4 6.03 pM/L.

Ultrasonography: both thyroids were hypoechogenic. Extensive fibrotic changes were observed. There were no lesions fitting a nodule.

Cytology resulted in Hashimoto's thyroiditis.

Clinical diagnosis: hypothyroidism, Hashimoto's thyroiditis.

Daily 100 microgram levo-tiroxine was advised with gradually increasing dose.

Follow-up examination 18 months later (3rd row of images):

Clinical presentation: the patient had no complaints except for gaining another 5 kg in weight.

Palpation: the thyroid was not palpable.

Functional state: euthyroidism on daily 75 microgram levo-tiroxine (TSH 2.43 mIU/L).

Ultrasonography: the sonographic pattern was unchanged. The volume of the thyroid was less than 33% of the previous volume.

Suggestion: to continue the replacement therapy with daily 75 microgram levothyroxine.

Comments.

1. It is noteworthy that the pattern of the thyroid is almost identical in the first and the follow-up examination. Analyze the appearances of the discrete hypoechogenic lesion in the dorsal part of the right lobe.

2. In most cases of severe hypothyroidism presenting goiter, the thyroid gradually decreases in size parallel with the normalization of the TSH.