Percutaneous Ethanol Injection for Benign Cystic and Mixed Thyroid Nodules

Objective: We aimed to determine the effect of percutaneous ethanol injection (PEI) on volume of cystic and mixed thyroid nodules, thyroid function tests (TFTs), antibody titers, and cytologic changes for 1 year.Methods: Fifty-five nodules from 53 patients with cystic and mixed properties treated with PEI were included. Nodule volumes, TFTs, and thyroid autoantibodies were analyzed at baseline, 6 months, and 12 months. Fine-needle aspiration biopsy (FNAB) was performed to PEI-treated nodules in the 12th month. Thyroid nodules were classified into three groups by structural properties (purely cystic, predominantly cystic, predominantly solid).Results: PEI caused a volume reduction of 80.7% at 6 months and 82.1% at 12 months, without any serious complications. PEI was repeated 1.4 ± 0.4 times with a mean total ethanol amount of 3.6 ± 3.1 mL. Volume reduction in the purely cystic nodules in the 6th and 12th months after PEI was greater than the volume reductions in predominantly cystic and predominantly solid nodules. We found that smaller nodules had greater volume reductions after PEI in the 12th month. During the study, patients remained euthyroid. Antithyroglobulin levels were decreased at 12 months. None of the FNAB results were compatible with a malignant or suspicious for malignancy cytology at the 12th month.Conclusion: PEI is an effective means of treatment for benign cystic and mixed thyroid nodules, without any serious side effects. We can also assume that PEI is not a trigger for autoimmunity and malignancy development over the short term.Abbreviations: anti-TG = anti–thyroglobulin; anti-TPO = anti–thyroperoxidase; AUS = atypia of unknown significance; CV = coefficient of variation; FNAB = fine-needle aspiration biopsy; fT3 = free triiodothyronine; fT4 = free thyroxine; PEI = percutaneous ethanol injection; TFT = thyroid function test; TSH = thyroid-stimulating hormone; US = ultrasonography