Clinical presentation: a 57-year-old woman was referred with subfebrility lasting for a month. At the beginning of her complaints her thyroids were painful.

Palpation: both thyroids were hard and tender.

Functional state: mild hyperthyroidism with TSH-level 0.01 mIU/L, FT4 24.7 pM/L, FT3 6.43.

Ultrasonography: there were multiple hypoechogenic areas with blurred borders within echonormal background. The vascularization was average.

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

Suggestion: steroid therapy.