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.

Morphological changes in a hyperfunctioning thyroid adenoma after percutaneous ethanol injection: histological, enzymatic and sub-microscopical alterations

Ultrasound-guided ethanol injection (PEI) is an effective treatment of autonomously functioning thyroid nodules (AFTN) but little is known about the tissue lesions induced by alcohol. We report morphological changes of an AFTN which was removed after successful PEI treatment. At histological evaluation, the adenoma showed multiple areas of coagulative necrosis with eosinophilic ghost follicles, hemorrhages, small vessel thrombosis and a wedge-shaped hemorrhagic infarction. The peripheral adenomatous tissue and the surrounding thyroid parenchyma were free of regressive changes and/or lympho-monocytic inflammatory reactions. Enzyme histochemistry confirmed the hyperfunctioning character of the lesion and showed reduction of succinic dehydrogenase and cytochrome-c-oxydase activity in the viable tissue surrounding the central necrotic areas. By electron microscopy, the hyperfunctioning follicular epithelium showed submicroscopical alterations of the adenomatous cells surrounding the areas of coagulative necrosis. These results suggest that control of hyperthyroidism, after PEI, is due to: a) directly induced, irreversible damage (coagulative necrosis and vascular thrombosis with hemorrhagic infarction) in the central areas of the lesion; b) potentially reversible damage (reduction of intracellular enzyme activity and ultrastructural changes) in the peripheral areas.