Fibrous invasive (Riedel's) thyroiditis with critical response to steroid treatment.

The Riedel's thyroiditis is an uncommon form of chronic thyroiditis characterized by an invasive fibrosclerosis of the gland, often involving the surrounding tissues. Usually, the only possible treatment is the surgical decompression of the tissues. We describe a case of aggressive Riedel's thyroiditis with severe compression and dislocation of trachea and esophagus. The surgical approach was uneffective, while an "ex juvantibus" steroid treatment, resulted in a dramatic regression of fibrosclerosis and a complete clinical remission. This report points out the possible effectiveness of corticosteroids in the treatment of selective disorders involving increased fibrogenesis.