Iodide-induced thyrotoxicosis in a thyroidectomized patient with metastatic thyroid carcinoma.
An unusual case of iodide-induced thyrotoxicosis is documented in this article. The patient was a 64-year-old euthyroid man with acromegaly. He also had multiple follicular and papillary thyroid carcinomas with a metastatic lesion in the lumbar vertebrae. After a total thyroidectomy, he became slightly hypothyroid, and the lumbar lesion began to incorporate 131I by scintigraphy. When an iodine-containing contrast medium happened to be injected, a transient increase of serum thyroid hormone level was observed. After complete thyroid ablation with 83 mCi of 131I, the oral administration of 100 mg of potassium iodide for 7 days induced a prominent increase of serum thyroid hormone level. These findings indicated that the metastatic thyroid carcinoma could produce excess thyroid hormone insofar as a sufficient amount of iodide was given. Although this is the first report of such a case, iodide-induced thyrotoxicosis may not be rare in patients with thyroid carcinomas because the Wolff-Chaikoff effect is thought to be lost, and the organic iodinating activity and lysosomal protease activity are well-preserved.
Yoshinari
M
M
Second Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka City, Japan.
Tokuyama
T
T
Okamura
K
K
Sato
K
K
Kusuda
K
K
Fujishima
M
M
D000172:Acromegaly / Q000150:complications; D000230:Adenocarcinoma / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D003287:Contrast Media / Q000009:adverse effects*; D007457:Iodine Radioisotopes / Q000009:adverse effects*; D007482:Iothalamate Meglumine / Q000009:adverse effects*; D009378:Neoplasms, Multiple Primary; D011183:Postoperative Complications / Q000139:chemically induced; D011877:Radionuclide Imaging; D013125:Spinal Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000556:secondary*; D013963:Thyroid Hormones / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000150:complications* / Q000473:pathology / Q000601:surgery; D013971:Thyrotoxicosis / Q000139:chemically induced*
D003287:Contrast Media; D007457:Iodine Radioisotopes; D013963:Thyroid Hormones; D007482:Iothalamate Meglumine