Chronic fibrous thyroiditis

This code represents Riedel's thyroiditis, a rare, chronic inflammatory condition characterized by dense fibrous tissue replacing normal thyroid parenchyma. It can extend beyond the thyroid capsule, potentially compressing adjacent structures like the trachea or esophagus.

Use this code when documentation specifically identifies chronic fibrous thyroiditis or Riedel's struma. This diagnosis is typically confirmed through biopsy demonstrating extensive fibrosis and inflammatory infiltrates. It is appropriate for patients presenting with a hard, fixed, and often painless thyroid mass.

• Differentiate from other forms of thyroiditis (e.g., Hashimoto's, subacute) which have distinct ICD-9 codes.
• Ensure documentation specifies "fibrous" or "Riedel's" to support this specific diagnosis.
• Consider additional codes for any associated complications, such as tracheal compression or hypoparathyroidism, if documented.