UpToDate®: 'Treatment of toxic adenoma and toxic multinodular goiter'

There are two clinical situations in which establishing the diagnosis of a toxic adenoma or toxic multinodular goiter is more difficult. First, the autonomously functioning tissue may be sufficiently diffuse that it is difficult to differentiate a toxic multinodular goiter from Graves' disease by thyroid scintigraphy alone. When it is important to distinguish these disorders, a high serum concentration of TSH receptor antibodies indicates Graves' disease, but a low titer does not exclude the diagnosis. Second, in iodine-induced hyperthyroidism, the exogenous iodine load can dilute the radioiodine tracer and result in