Clinical data: a 76-year-old woman was referred for percutaneous etanol sclerotherapy. The patient noticed a suddenly developed lump in the left thyroid 4 month ago causing difficulties in swallowing. Within 2 weeks after removing 19 mL cystic fluid the cyst had refilled. Cytology resulted in benign cystic lesion.

Palpation: a large nodule in the left lobe.

Hormonal evaluation indicated euthyroidism (TSH 0.95 mIU/L).

Ultrasonography. The thyroid was echonormal. The left lobe contained a large cystic nodule with a minimally hypoechogenic solid part on the dorsal part. The lesion presented with a perinodular blood flow.

Six sessions of sclerotherapy were applied.