Pathology of tracheal tumors.

Malignant involvement of the trachea predominantly results from direct spread of neighboring tumors to the tracheal wall. Primary tracheal malignancies show a low incidence of approximately 0.1 in every 100,000 persons per year, squamous cell carcinomas and adenoid cystic carcinomas accounting for about two-thirds of adult primary tracheal tumors. The etiology of squamous cell carcinoma and its premalignant lesions is strongly associated with tobacco smoking. Patients with tracheal malignancies show an unfavorable prognosis, with reported 5- and 10-year survival rates of 5% to 15% and 6% to 7%, respectively, for all types of tracheal carcinoma.