Treatment of recurrent thyroid cysts with ethanol: a randomized double-blind controlled trial.

Thyroid nodules are prevalent; when evaluated by ultrasonography (US), 15-25% of solitary thyroid nodules are cystic or predominantly cystic, and most are benign. Simple aspiration is the treatment of choice, but the recurrence rate is 10-80% depending on the number of aspirations and the cyst volume. The aim of this study was to evaluate the effect on recurrence rate of benign recurrent thyroid cysts in a double-blind randomized study comparing ethanol instillation with instillation of isotonic saline and subsequent complete emptying. Sixty-six consecutive patients with recurrent and benign (based on US-guided biopsy) thyroid cysts (>or=2 ml) were randomly assigned to either subtotal cyst aspiration, flushing with 99% ethanol, and subsequent complete fluid aspiration (n = 33), or to subtotal cyst aspiration, flushing with isotonic saline, and subsequent complete fluid aspiration (n = 33). In case of recurrence (defined as cyst volume >1 ml) at the monthly evaluations, the treatment was repeated but limited to a maximum of three treatments. Procedures were US-guided, and patients were followed for 6 months. Age, sex, number of previous aspirations, pretreatment cyst volume, and serum TSH did not differ in the two groups. Cure (defined as a cyst volume