Clinical presentation. A 51-year-old man was referred for evaluation of a thyroid nodule discovered by the patient himself.

Palpation: a firm nodule in the right lobe.

Result of blood tests: TSH 1.20 mIU/L.

Ultrasonography. The thyroid was echonormal. A large cystic nodule occupied almost the entire right lobe. The nodule had echonormal solid parts. The type of the cyst was doubtful before aspiration of 14 mL brown fluid, however thereafter it became evident that this is a central-type cystic nodule.

Aspiration cytology resulted in non-diagnostic cystic lesion.

Suggestion: Repeat ultrasound in a year, if the cyst refills than sooner.

Comment. The echogenicity of a relatively large solid part of a cystic lesion frequently changes after aspiration. I am not aware of any publications related to this issue; I describe the echogenicity as it looks like prior to aspiration.