[Inappropriate TSH: from common etiologies to the rare TSH secreting pituitary adenoma].

Dealing with a patient with hyperthyroidism and goiter, the association of high values of free T4 or free T3 with a normal TSH, may suggest the presence of errors in the measurement as well as the possibility of a TSH secreting pituitary adenoma. However, a very similar clinical picture may occur in the syndrome of resistance to thyroid hormone. The differential diagnosis is made by history and appropriate laboratory tests before considering pituitary imaging.

Tomographic imaging of the human thyroid using 124I.

After receiving between 100 and 300 mu Ci of the positron-emitting radioisotope 124I (half-life, 4.2 days), 64 patients with a variety of thyroid disorders were imaged with a high resolution positron camera. A 3-dimensional image of the distribution of radioiodine uptake within the thyroid was obtained from a single 10- to 15-min scan.

[Euthyroid sick syndrome].

The "euthyroid sick syndrome", representing the changes of thyroid hormone metabolism in disease, embraces the following hormonal changes: 1) A decrease in serum T3 levels which is often accompanied by an increase in rT3 levels. Serum T4 levels remain normal. These changes are extremely frequent in many varied diseases.