Abstract
Involvement of the thyroid cartilage attracts a high T rating in all systems of classification for carcinoma of the larynx. Evaluation of 145 patients with laryngeal cancer treated by total laryngectomy emphasizes the difficulties of preoperatively determining cartilage invasion. The operative specimen was serially sectioned and studied to determine the means by which ossified and nonossified thyroid cartilage is invaded by carcinoma. A minimum 5-year follow-up of these cases indicates the prognostic significance of such invasion.