A Method for the Preoperative Estimation of Function in Thyroid Tumors: Its Significance in Diagnosis and Treatments*†

MUCH has been learned about the relative function of thyroid nodules (1) by giving radioactive iodine (I131) to patients with nodular goiter and making radioautographs from the excised tissue. With this method we have shown that some nodules have little or no function whereas, on the basis of unit area, others are more active than the extra-nodular thyroid tissue. The term “hyperfunctioning nodule or adenoma” has been used by some to imply the presence of clinical thyrotoxicosis (2, 3). New information revealed by radioautographs shows that nodules with excessive function may occur in patients without as well as in patients with thyrotoxicosis (1); therefore, the terms “hyperfunctioning nodule with thyrotoxicosis” and “hyperfunctioning nodule without thyrotoxicosis” have become necessary (1,4). A satisfactory method of estimating the relative function of thyroid nodules before their removal is of value in determining their nature. It assists in the anticipation of possible malignancy. It indicates the presence of a hyperfunctioning nodule even before the onset of overt thyrotoxicosis. It assists in differentiating between thyrotoxicosis resulting from a hyperfunctioning nodule on the one hand, and the diffuse hyperplasia of Graves' disease with an incidental nodule on the other.