Clinical presentation: A 72-year-old woman was referred for aspiration cytology of a nodule described as suspicious on previous ultrasound examination. The patient has been treated for hypothyroidism for more than three decades. She noticed a sudden increase in the size of the right lobe in the last couple of months and a deepening of her voice. Laryngology revealed intact function of the recurrent nerve.

Palpation: The right lobe was enlarged and hard on palpation.

Hormonal evaluation: TSH 9.01 mIU/L, FT4 12.2 pM/l on daily 75 microgram levothyroxine. The aTPO level was above 1300 U/mL.

Ultrasonography. The right thyroid was composed of hypoechogenic areas divided by less hypoechogenic fields. None of the lesions corresponded to a nodule in pathological sense. The left thyroid was decreased in size.

Cytology resulted in Hashimoto's thyroiditis.

Right lobectomy was performed. Histopathology disclosed Hashimoto's thyroiditis without any nodules.

Comment. The discrete lesions are clearly not nodules in pathological sense, neither the shape nor the borders fit to nodule. On the other hand, the possibility of a MALT-type thyroid lymphoma had to be considered even after the cytology.