Severe thyrotoxicosis due to hyperfunctioning liver metastasis from follicular carcinoma: treatment with (131)I and interstitial laser ablation

Liver metastases from differentiated thyroid tumors are unusual clinical findings, and are only rarely hyperfunctioning. We report a case of thyrotoxicosis caused by a huge and surgically unresectable liver metastasis from follicular thyroid cancer, unresponsive to treatment with large doses of thionamides. To avoid the hazardous side effects of (131)I treatment in a severely thyrotoxic patient, a preliminary debulking of the liver mass was performed by means of percutaneous interstitial laser photocoagulation. Three treatments (total energy delivery: 7200 J) were performed under ultrasound guidance, with no serious complications, during a 2-week period. One month later, serum thyroid hormones had decreased, general condition was improved, and magnetic resonance evaluation revealed large and well-defined areas of necrosis of metastatic tissue. During the following 10 months, the patient underwent 3 radioiodine treatments. Eighteen months after diagnosis, thyroid hormones were within normal levels, liver mass decreased, and the clinical condition markedly improved. The combination of percutaneous interstitial laser photocoagulation treatment and radioiodine therapy made possible the effective management of a hyperfunctioning and surgically untreatable liver metastasis from thyroid follicular carcinoma, avoiding the side effects of (131)I therapy in a thyrotoxic patient and increasing the effectiveness of radioiodine-induced neoplastic tissue ablation.