Riedel thyroiditis is typically characterized by a firm, fixed, and typically asymptomatic enlargement of the thyroid. It is a very unusual kind of thyroiditis that causes the parenchymal tissue to gradually change into connective tissue. This is a solid, visible goiter that can lead to discomfort, compressive symptoms, and damage to nearby tissues such as the parathyroid glands, neck muscles, and vocal cord paralysis.
Riedel thyroiditis is a rare, inflammatory illness of the thyroid gland characterized by thick fibrosis that replaces normal thyroid tissue. The fibrotic process spreads to nearby neck structures and goes past the thyroid capsule. This distinguishes RT from other thyroid illnesses that are inflammatory or fibrotic. This is distinct from the fibrosing type of Hashimoto’s thyroiditis due to its extension beyond the thyroid. It leads to low calcium levels, pressure on the trachea, and problems with the recurrent laryngeal nerve.
Because of the existence of a rocky hard thyroid mass, the clinical picture is typically one of thyroid cancer. Riedel’s thyroiditis is extremely rare, and its frequency has dropped substantially in recent decades for unexplained causes.
The proper and accurate diagnosis of Riedel’s Thyroiditis is made with the help of certain tests. To detect thyroid hormone abnormalities or increased antibodies, blood tests are required, as well as an ultrasound scan is also used to examine the thyroid gland and the surrounding area. Riedel’s thyroiditis is frequently diagnosed with a fine-needle aspiration biopsy.
Riedel’s Thyroiditis Symptoms
Riedel thyroiditis is most commonly characterized by an enlarged, hard thyroid. Obstructive symptoms are common when neck structures are involved. The other symptoms that are prevalent in the patients are dysphagia, dyspnea, venous sinus thrombosis, and stridor. All these symptoms occur due to the involvement of esophageal, tracheal, vascular, and recurrent laryngeal nerves.
Some other symptoms are also found on examination by the doctors. These include hypoparathyroidism due to parathyroid gland involvement, a hard mass in the anterior of the neck, obstructed airway, hoarseness, and hypothyroidism.
Riedel’s Thyroiditis Causes
Riedel thyroiditis (RT) has no known cause, but it is linked with a new group of rare illnesses known as IgG4-related chronic disease (IgG4-RSD). One pathophysiology idea claims that RT is caused by an autoimmune reaction. Another idea claims that RT is a primary fibrotic illness.
The following are some other causes of Riedel’s Thyroiditis:
- Retroperitoneal fibrosis.
- Mediastinal fibrosis.
- Orbital fibrosis.
- Primary sclerosing cholangitis.
Riedel’s Thyroiditis Treatment
Because of the rarity of the disease, there is no conventional treatment for Riedel thyroiditis. The core of medical treatment for Riedel’s Thyroiditis is glucocorticoids. It is best to begin using glucocorticoids early in the disease phase to maximize their anti-inflammatory effects. The dosage that is helpful in the treatment is prednisone 15mg to 100mg.
The therapeutic response is variable, with some individuals exhibiting a significant recovery of the symptoms, and others exhibiting a complete lack of response. The lack of response to glucocorticoids may be caused by an increase in fibrosis in late-stage disease, as opposed to inflammation, which is more prevalent in early-stage disease.
The other medication that is helpful for the treatment of this rare illness is Tamoxifen which is a selective estrogen receptor modulator. A SERM is used to treat Riedel thyroiditis and other systemic fibrosing illnesses. It causes the production of tumor growth factor-beta, a powerful growth inhibitor.
The various kinds of immunosuppressive drugs are also preferred for managing this Riedel’s thyroiditis. One such drug is Mycophenolate mofetil which has anti-fibrotic effects and is used to treat systemic fibrosis. It transforms into mycophenolic acid, which suppresses the generation of antibodies by T and B cells.
Because Riedel thyroiditis (RT) is so uncommon, it is impossible to conduct controlled research on RT therapy. Medical therapy recommendations are based on experience. Corticosteroids and tamoxifen are examples of pharmacologic treatment. For patients with RT, surgery is used to confirm the diagnosis as well as relieve tracheal constriction.
Riedel’s thyroiditis vs Hashimoto’s
The fibrosing type of Hashimoto’s thyroiditis is distinguished from Riedel’s thyroiditis by significant fibrous development without expansion into the surrounding structures. On the other hand, Riedel’s Thyroiditis is a rare disease with a rate of 0.05 percent or less in surgical thyroid series and it is described alone or in conjunction with other autoimmune disorders such as thyroid cancer.
Riedel’s thyroiditis and Hashimoto’s are associated with each other due to the presence of thyroid antibodies in RT patients. Despite this, the prevalent opinion in the medical community at present is that these are two distinct entities that need to be separated from one another.