THE SERUM thyroglobulin (Tg) concentration is elevated in some patients with differentiated thyroid carcinoma.1 Plasma calcitonin (CT) measurement is a specific screening test for medullary carcinoma of the thyroid.2 The purpose of our study was to assess the clinical value of measuring plasma thyroglobulin and calcitonin levels in the evaluation of nontoxic goiter.
Patients and Methods
Patients with goiter who attended the endocrine clinics of the Wadsworth Veterans Administration Hospital or the University of California, Los Angeles, Hospital had blood samples drawn during routine visits. All patients had been examined for goiter by standard techniques, including thyroid function tests, antithyroid antibodies, and radioiodine thyroid scans. Thyroid size was estimated by palpation, and nodules were measured with a plastic ruler. In patients with single nodules discovered by palpation, the thyroid size was estimated by adding the mass of the nodule to that of the normal gland, which was assumed