Clinical presentation: a 37-year-old woman was referred for an evaluation of neck pain and subfebrility lasting for three weeks. Her complaints have spontaneously elapsed two days before investigation.

Palpation: the left thyroid was firm and not tender on palpation.

Functional state: subclinical hyperthyroidism with TSH-level 0.01 mIU/L, FT4 18.1 pM/L, FT3 4.88 pM/L, ESR 28 mm/H, CRP 7.52 mg/L.

Ultrasonography: the right thyroid was intact, while there was a hypoechogenic nodule and several hypoechogenic lesions with blurred borders in the left lobe. The vascularization was increased in one and absent in the other hypoechogenic lesion.

Cytological diagnosis: benign colloid goiter in the case of the nodule and subacute, granulomatous de Quervain's thyroiditis in the cases of hypoechogenic lesions with blurred borders.

Suggestion: no therapy.

Follow-up investigation: the echo structure of the thyroid completely normalized 12 months after the initial investigation except for the nodule in the left lobe, which did not change neither in size nor in echogenicity.