Clinical presentation: A 47-year-old woman requested a follow-up examination. We met her three years ago when a cystic nodule was found. We could diminish the size of the lesion by aspirating 3 mL fluid. The cyst has refilled since the last examination.

Palpation: an elastic nodule in the right lobe.

Functional state: euthyroidism with TSH 2.94 mIU/L.

Ultrasonography. The thyroid was echonormal. There was a cystic nodule in the right lobe. The lesion presented numerous comet-tail artifacts.

3 mL brown fluid was aspirated. Cytology resulted in benign cystic degeneration.

Comments. This case presents various presentations of a comet-tail artifact which might appear beside the typical form as a bright or pale granule or line lacking the dorsal tail.