Riedel’s thyroiditis is a rare chronic inflammatory disease of the thyroid gland characterized by invasion of the thyroid gland and surrounding structures with dense fibrous tissues. It is a very rare condition. At the Mayo clinic, 37 cases were diagnosed in a series of 57,000 thyroidectomies that were performed between 1920 and 1984. The operative incidence was 0.06% and the overall incidence in outpatients was 1.06 per 100,000 . It is most often seen in women. In a review of 178 patients, 83% were reported to be women.
Riedel’s thyroiditis is associated with hypothyroidism, hypoparathyroidism, compression of the trachea, larynx, carotid sheath and esophagus. It may also cause invasion of adjacent muscles and mediastinum. Riedel’s thyroiditis is also associated with other fibrous inflammatory processes, including retroperitoneal fibrosis, orbital pseudotumour, mediastinal fibrosis, sclerosing cholangitis and fibrosis in other organ systems . We present a rare case of Riedel’s thyroiditis that presented a diagnostic dilemma but had a good response to high dose of steroids, with no relapse after a year of treatment.