Thyroid scintigraphy of hyperthyroxinemia.

The term "hyperthyroxinemia" encompasses clinical syndromes associated with elevated levels of thyroid hormone in the presence of increased, normal, or decreased thyroid function. The clinical presentation (i.e., history and physical examination), in vitro thyroid function tests, as well as radioisotope thyroid imaging all play key roles in the diagnosis of the underlying thyroid disorder. Many of these disorders and their appearance on thyroid scintigraphy are presented in this atlas.

Familial dysalbuminemic hyperthyroxinemia associated with multinodular goiter and elevated radioiodine uptake. A case report.

Familial dysalbumenic hyperthyroxenemia characterized by elevations in serum total thyroxine (T4) and free-thyroxine index and normal free T4 and radioiodine uptake has been previously described. This syndrome is secondary to an autosomal dominant inheritance in which affected individuals are mistakenly diagnosed as thyrotoxic because of the elevation of serum levels of total T4 and free T4. The excess T4 level is caused by the presence of an abnormal serum protein that binds excess T4, thereby raising the level of total T4. The authors report the case of a patient with familial dysalbumenic hyperthyroxenemia who presented with superimposed multinodular goiter and an elevated 24-hour radioiodide uptake.