Abstract
Riedel's thyroiditis (RT) is a rare chronic inflammatory disease of the thyroid gland. It is characterized by a fibroinflammatory process that partially destroys the gland and extends into adjacent neck structures. Its clinical manifestation can mask an accompanying thyroid neoplasm and can mimic invasive thyroid carcinoma. Therefore, diagnosis can be difficult prior to surgical removal of the thyroid, and histopathologic examination of the thyroid is necessary for a definite diagnosis. The concurrent presence of RT and other thyroid diseases has been reported. However, to our knowledge, the association of RT with acute suppurative thyroiditis and micropapillary carcinoma has not been reported. We report a rare case of concurrent RT, acute suppurative thyroiditis, and micropapillary carcinoma in a 48-year-old patient.