Riedel Fibrosing Thyroiditis

**Semantic type:** Disease or Syndrome

**Definition:** An inflammatory disorder of unknown etiology that affects the thyroid gland. It is characterized by extensive fibrosis of the thyroid parenchyma. The fibrosis extends beyond the thyroid gland capsule to the adjacent structures.

**Synonyms:** - Riedel Thyroiditis - Riedel's Fibrosing Thyroiditis