Treatment of cystic lesions of the thyroid by ethanol instillation.

We analyzed the results of ethanol sclerotherapy in 61 patients with cystic thyroid lesions which recurred after aspiration. Cytologic study showed all of the lesions to be benign. The patients were followed clinically and ultrasonically 1 month and 6 or more months after treatment. If the cystic lesions recurred, repeated treatment was offered. During the follow-up, 36 (59.0%) patients experienced no recurrence after the initial treatment and 5 (8.2%) patients received treatments 2 or more additional times. In 44 (72.1%) of the 61 patients, the cystic lesion almost disappeared or decreased in size, but in 17 (27.9%) patients it did not decrease. Four patients underwent surgery after the ethanol sclerotherapy. Although no severe complications were observed, there were complaints of slight pain in 12 patients, severe pain in 1 patient, and a drunken feeling in 1 patient. We consider instillation of ethanol into recurrent cystic lesions of the thyroid to be a simple, safe, economical, and effective treatment.