Clinical presentation: a 67-year-old man was referred for aspiration cytology. Ha had pain in the region of the left thyroid and fever for 5 weeks. These complaints spontaneously resolved within a week. 6 days before the present examination his complaints recurred but in the right side of the neck.

Palpation: the right thyroid was hard and painful, but the left lobe was firm and painless.

Functional state: hyperthyroidism with TSH-level 0.05 mIU/L, FT4 39.8 pM/L, erythrocyte sedimentation rate 71 mm/H.

Ultrasonography: both lobes contained multiple hypoechogenic areas with blurred borders. The vascularization was absent in the right, and increased in the left lobe.

Cytological and final diagnosis: subacute, granulomatous de Quervain's thyroiditis.