-used to differentiate between thyrotoxicosis and thyroditis
-elevated and diffuse - graves
-normal/elevated focal area - nodule
-low/absent - thyroiditis
1. young age (<30 years)
2. male sex
3. a history of head or neck irradiation
5. rapid nodule growth, larger nodules, and hoarseness.
Hot nodules are rarely malignant
-if euthyroid w/ nodules - U/S; >1cm should be biopsied (10-15% risk of ca), else may be if cancer rfs
Methimazole is generally recommended as first-line antithyroid therapy, as propylthiouracil has been associated with elevated aminotransferase levels and a higher rate of serious adverse effects on the liver than occur with methimazole. An exception is women who are in the first trimester of pregnancy, during which methimazole has been associated with possible teratogenicity. Propylthiouracil is also preferred in patients with an allergy to methimazole. With either drug, patients should be counseled about the risk of the rare but severe side effects of agranulocytosis, hepatitis, and vasculitis. Rarely, severe hepatic necrosis has been reported, predominantly with propylthiouracil.