First examination (1st and 3rd rows of images):

Clinical presentation: a 39-year-old woman visited us. She had upper airway infection 4 month earlier. At the time of present investigation both sides of the neck became tender, painful and fever had developed. ESR was 43 mm/H, CRP 18.4 mg/L. 3 courses of antibiotics was administered with only limited success. The patient was sent to oncological department for further evaluation. The patient surfed on the net and visited us because she thought to have de Quervain's thyroiditis.

Palpation: the right thyroid was painful while the left was tender. Both were hard.

Laboratory data: TSH 0.001 mIU/L, FT4 29.9 pM/L, ESR 40 mm/H, CRP 15.2 mg/L.

Ultrasonography: both thyroids were echonormal and presented hypoechogenic areas with ill-defined borders and decreased vascularization.

Cytology was consistent with de Quervain's thyroiditis although multinucleated giant cells were not present on the smears.

Suggestion: ceasing antibiotics and steroid therapy.

6 weeks after initial examination (2nd row of images):

Clinical presentation: the complaints of the patient have stopped on the first day of steroid administration and did not recur later.

Palpation: no abnormallity.

Laboratory data:

• 6 weeks after initial investigation. Hypothyroidism with TSH 19.5 mIU/L, FT4 8.41 pM/L, ESR 6 mm/H, CRP 1.6 mg/L.

• 3 month later. Euthyroidism which remained in the following 10 months.

Ultrasonography. The size of the thyroids became normal. The hypoechogenic areas significantly decreased but around 10% of the lobes were already hypoechogenic. The vascularization became normal.

Suggestion: yearly follow-up until the echo structure will be normalized.

Comments.

1. In significant number of cases the pathognomic multinucleated giant cells are absent on FNAC. In such cases when inflammatory cells and colloid precipitate are on the smear, the diagnosis of de Quervain's thyroiditis has to be considered. If the clinical picture and laboratory data are typical, a combined clinical-ultrasonographic-cytologic diagnosis of de Quervain's thyroiditis can be given.

2. We suggest follow-up to our patients with de Quervain's thyroiditis until the echo structure will be normal. It requires in most cases 12-24 months.