Percutaneous ethanol injection of large thyroid cystic nodules

To evaluate the effect of percutaneous ethanol injection (PEI) in the treatment of large compressive thyroid cystic nodules (TCN), we studied 20 patients, potential candidates for surgery (tracheal displacement, nodule volume over 10 mL at ultrasonography) and not cured by aspiration alone: 14 experienced a recurrence after two complete evacuations of cystic fluid (watery nodules, WN); in six an aspiration was impossible because the cystic fluid was very thick (viscous nodules, VN). To exclude malignancy, both cytocentrifugate from WN and the smears from VN were examined. WN were treated with 1-4 sessions of conventional PEI; in VN a first PEI session was performed with the purpose of reducing the density of cystic fluid; then if cystic fluid was successfully aspirated, one or more PEI sessions were performed. Thyroid palpation, ultrasonography with nodule volume assessment, and assays for FT₃, FT₄, and TSH were performed 1 and 6 months after the last PEI. At month 6, 17 patients (85%) had volume reduction of more than 90% of the initial nodule volume; in 2 patients (10%) there was a reduction between 50 and 90%, and in one patient (5%) an appreciable swelling persisted after 3 injections. Nodule volume was significantly decreased below baseline at month 1 (10.9 ± 13.3 vs 39 ± 24 mL, p <0.001), with a further reduction at month 6 (5 ± 11.7 mL, p <0.01 vs 1st month value). In most of the nodules the cystic portion completely disappeared; the residual tissue showed fibrous features, often with calcifications. In 11 patients follow-up was prolonged over the sixth month (15 ± 4 months); the nodule volume did not significantly differ from the sixth month (3 ± 2.2 mL) and the end of the follow-up (2.8 ± 2.3 mL). In conclusion, we demonstrate that PEI may be a safe and effective procedure in the treatment of large TCN.