Diagnostic discriminants of thyroid cancer.

One hundred ten consecutive patients with histologically proved thyroid carcinoma were studied in relation to cell type, age, sex, presence of metastases, and results of thyroid scintiscanning and ultrasonography. Forty-four percent of these patients presented with a normally functioning, or warm, nodule on scintiscan. Nineteen percent presented with ultrasonographic findings of a cystic lesion. The physiologic circumstances that explain these findings have been discussed. On the basis of this study, as well as other reported series, it is concluded that both scintiscanning and ultrasonography are not reliable discriminants in the diagnosis of thyroid cancer.