Clinical presentation: A 24-year-old woman was referred for evaluation of an elevated TSH and a multinodular goiter detected on evaluation of weight gain. We met the patient 8 years ago, when the examination resulted in euthyroid Hashimoto's thyroiditis based on a 60% echogenicity index despite a normal aTPO level (10 U/mL). At that time, we did not find any nodules in pathological sense.

Palpation: Both lobes were moderately firm.

Laboratory tests: TSH 5.26 mIU/L, FT4 12.7 pM/L, aTPO 7 U/mL.

Ultrasound. Great proportion of the thyroid was composed of hypoechogenic areas. These were not of geometrical shape, had an irregular border and presented echonormal tissue. None of them corresponded to a true nodule.

Aspiration cytology from the hypoechogenic lesion in the isthmus resulted in Hashimoto's thyroiditis.

Comment.

1. The lesions are unlikely being nodules in pathological sense, the hypoechogenic discrete areas correspond to more active foci of Hashimoto's thyroiditis.

2. Regarding the borders, the lesions have spiculated margins which is a normal finding in the infiltrative process of Hashimoto's thyroiditis.