Riedel thyroiditis is a very rare form autoimmune thyroiditis. It is sometimes considered as a manifestation of a wider systemic disease with fibrosis of the retroperitoneum, mediastinum, as well as lymphocytic infiltration of extraocular orbital muscles, salivary and lacrimal glands 4. Most recently all these pathologies are considered as manifestations of the same pathology known as IgG4 disease.
Patients present with a painless thyroid mass that can be rapidly growing. As with other thyroid disorders, there may be symptoms from local compression such as dysphagia or stridor. On examination, there is usually a thyroid goiter which is fixed and hard, sometimes described as stony or woody.
The condition is characterized by replacement of the thyroid gland with fibrotic tissue which extending to the surrounding tissues, unlike end stage Hashimoto thyroiditis in which fibrosis is confined to the capsule. The thyroid gland can become hardened as a result. Only 30% of patients are hypothyroid
- IgG4-related sclerosing disease, which also includes
The thyroid can appear homogeneously hypoechoic with the poor demarcation of the gland borders as the fibrotic invasion of the adjacent fat or anatomical structures progresses.
This may demonstrate compression of local structures by an enlarged thyroid with low attenuation change within areas of the involved thyroid gland.
The fibrosing thyroid gland appears low on T1 and T2 and can have a variable pattern of enhancement.
- 1. Ozgen A, Cila A. Riedel's thyroiditis in multifocal fibrosclerosis: CT and MR imaging findings. AJNR Am J Neuroradiol. 2000;21 (2): 320-1. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 2. Shawker TH, Paling MR, Weintraub B. Dysphagia due to thyroid immobilization: value of real-time sonography. AJR Am J Roentgenol. 1981;136 (3): 601-2. AJR Am J Roentgenol (citation) - Pubmed citation
- 3. Rossi SE, Mcadams HP, Rosado-de-christenson ML et-al. Fibrosing mediastinitis. Radiographics. 21 (3): 737-57. Radiographics (full text) - Pubmed citation
- 4. De lange WE, Freling NJ, Molenaar WM et-al. Invasive fibrous thyroiditis (Riedel's struma): a manifestation of multifocal fibrosclerosis? A case report with review of the literature. Q. J. Med. 1989;72 (268): 709-17. Q. J. Med. (abstract) - Pubmed citation
- 5. Aster JC. Robbins Basic Pathology. Saunders. (2012) ISBN:1437717810. Read it at Google Books - Find it at Amazon
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