Clinical presentation: A 59-year-old woman was referred for evaluation of hyperthyroidism. She suffered from a painful thyroiditis five years ago which was treated with non-steroid anti-inflammatory drug. She had no complaints in the upcoming five years. Two months before the present examination she had an upper airway infection. After ceasing the infection, difficulties in swallowing still remained. She lost 6 kg in weight.

Palpation: a significantly enlarged, firm multinodular goiter.

Hormonal investigations: TSH 0.001 mIU/L, FT4 24.1 pM/L, FT3 5.52 pM/L, aTPO 38 U/mL, anti-hTg 67 U/mL, TSAb in the normal range, CRP 0.41 mg/L.

Ultrasonography revealed a multinodular goiter. The lesions were echonormal and hypoechogenic. The non-nodular area of the thyroid was minimally-moderately hypoechogenic and had a pseudolobular pattern.

Aspiration cytology was performed from the large nodule in the right lobe. Cytological report was benign colloid goiter.

Final diagnoses. Toxic multinodular goiter. Lymphocytic thyroiditis.

Suggestion. Daily 10 mg methimazole and total thyroidectomy when FT4 turns to normal.