Comparison between ethanol sclerotherapy and emptying with injection of saline in treatment of thyroid cysts.

We compared the results of ethanol sclerotherapy in thyroid cysts with emptying of cysts and instillation of saline. Twenty-six patients with recurrent thyroid cysts were treated with cyst aspiration and subsequent ethanol sclerotherapy. A control group of 44 patients was submitted to cyst aspiration and subsequent injection with isotonic saline; among them 20 had previously been treated with repeated aspirations of the cyst fluid. The patients were followed up clinically and ultrasonically 1 and 12 months after treatment. Cure was defined as the absence of any residual cystic lesion or an ultrasonic cyst volume less than 50% of basal after 12 months from the start of treatment. Cytological study showed all of the lesions to be benign. Of the 44 patients in the saline group 16 (36%) were cured, among whom 6 of 20 had previously been submitted to repeated aspirations. Among the 26 patients treated with ethanol sclerotherapy 20 (77%) were cured. Statistical analysis revealed a significantly higher effectiveness of treatment with ethanol than that with emptying and saline instillation (chi-square, P = 0.002) or with repeated aspiration and saline instillation (chi-square, P = 0.003). Slight pain was observed in two patients treated with saline and five treated with ethanol sclerotherapy. Three patients treated with ethanol sclerotherapy presented severe pain and one transitory hyperthyroidism. We conclude that ethanol sclerotherapy is effective and safe in the treatment of thyroid cysts.