Scintigraphic features of autoimmune thyroiditis

The term autoimmune thyroiditis encompasses multiple inflammatory condition s of the thyroid gland, each with variable clinical manifestations. The mor e acute forms, silent (painless) thyroiditis and postpartum thyroiditis, ar e associated with transient hyperthyroidism and are sometimes mistaken for Graves disease. The chronic form, Hashimoto thyroiditis (chronic autoimmune thyroiditis), results in goiter and eventual hypothyroidism unless it is r ecognized and treated promptly. Thyroid uptake measurements and scintigraph ic findings (usually obtained with technetium-99m or iodine-123) play a com plementary role along with thyroid function testing in differentiating auto immune thyroiditis from other thyroid diseases, thereby influencing treatme nt. In some cases, histologic evaluation of biopsy specimens is required to yield the definitive diagnosis. Knowledge of the entire spectrum of these disorders is essential for appropriate case management.