Laryngeal involvement by thyroid disease.

Thyroid tissue or neoplastic derivatives therefrom in the larynx or trachea have their genesis in either ectopia or a direct invasion by carcinoma of the thyroid gland proper. The benign lesions are found preponderantly in patients from regions in which goiter is endemic, and they may represent as much as 7% of all benign tracheal tumors. Laryngotracheal invasion by thyroid carcinoma also has a frequency of approximately 7%, with all histologic types represented.