Clinical presentation: A 38-year-old man was referred for ethanol sclerotherapy. The patient noticed a nodule 2 months ago. On aspiration cytology 11 mL fluid was removed, cytology resulted in non-diagnostic puncture. The patient noticed that the cyst had refilled within 2 weeks.

Palpation: The right lobe had an elastic nodule.

Result of blood test: TSH 0.90 mIU/L.

Ultrasonography. The thyroid was echonormal. There was a large cystic nodule in the right lobe. The type of the cyst could not be determined, the lesion contained ragged, mostly echonormal solid fragments. is was closest to the spongiform-type subgroup. There were numerous echogenic figures within the solid and cystic part. Some of the were clearly caused by back wall posterior enhancement, several typical long-tail comet-tail artifacts were also present. The left lobe had a small, insignificant lesion.

11 mL brown fluid was aspirated. Cytology there were numerous macrophages in bloody background. A few compact papillary fragments could be identified. The nuclear details could not be judged except for one nucleus which contained an inclusion. Our report was suspicion of papillary carcinoma.

Histopathology disclosed papillary carcinoma.

Comments.

1. The type of the cysts is not evident, but it is closer to a peripheral-type cyst.
   
2. The echogenicity of the solid part is again difficult-to-judge, relatively large intact solid areas were echonormal.
   
3. The different echogenic figures included comet-tail artifacts with long tail - this is a very unusual finding in papillary carcinoma.