Clinical presentation: A 27-year-old woman was referred for aspiration cytology. On ultrasound multiple hypoechogenic nodules were described. She was treated for hypothyroidism 6 years ago.

Palpation: Both lobes were moderately firm.

Hormonal investigation: euthyroidism on daily 75 microgram levothyroxine (TSH 0.92 mIU/L, aTPO 766 U/mL).

Ultrasonography revealed a minimally hypoechogenic thyroid. There were numerous hypoechogenic areas which had irregular shape. The thyroid displayed pronounced fibrotic changes. None of the discrete areas fit to a nodule in pathological sense.

Aspiration cytology was performed form one of the hypoechogenic areas and resulted in Hashimoto's thyroiditis.

Comments.

1. This is one of the typical ultrasound presentations of Hashimoto's thyroiditis. In contrast with a true nodule, the hypoechogenic areas in Hashimoto's thyroiditis are numerous and have an irregular shape.

2. In my practice I perform aspiration cytology in each patient who was told harboring a nodule. Although this is clearly superfluous in cases like this one, this is the only way to decrease the anxiety caused by the false diagnosis of nodule.