Thyroglobulin in benign and malignant thyroid disease.

Thyroglobulin (TG) is a 19S glycoprotein produced by normal thyroids and almost all nonmedullary thyroid cancers. Radioimmunoassays measure serum levels of TG, and these levels are abnormally elevated in patients with metastatic thyroid cancer. Data from our study show that TG measurement is not effective in screening high-risk populations for thyroid cancer. Nevertheless, serum TG determinations are useful for assessing the presence and possibly the extent of residual or recurrent nonmedullary thyroid cancer in patients who have undergone total thyroidectomy.