Surgical and pathological changes after percutaneous ethanol injection therapy of thyroid nodules

Few data exist on the operative and pathological findings in patients having undergone previous percutaneous ethanol injection (PEI) therapy of thyroid nodules. We report here our experience with 13 patients operated on by the same surgical team. Two pathologists, both blinded to the previous PEI treatment, carried out histological evaluation. Reasons for surgery included PEI failure, suspicion of malignancy, and tracheal compression. The operations did not pose any special problem from the technical point of view, and the postoperative courses were uneventful. One patient who had a second operation developed hypoparathyroidism, and laryngeal nerve palsy was never observed. The histological diagnosis was hyperplastic or adenomatous nodule in 12 cases and papillary thyroid cancer in 1. No difficulty was found in evaluating the nodule capsule and surrounding vessels. In two lesions, nuclear enlargement and clearing were identified in thyroid follicles immediately adjacent to necrotic or scarred areas. These changes were considered reactive. In conclusion, patients previously treated by PEI were operated on without special technical problems. Histological diagnosis was not hindered, and there was no difficulty in ruling out malignant lesions. PEI, however, should be performed only by skilled operators, and incidental ethanol seepage throughout the nodule capsule must be carefully avoided.