Radiologic and pathologic abnormalities of the trachea in older patients with cystic fibrosis.

The possibility of tracheal enlargement in older patients with cystic fibrosis was investigated by examining chest radiographs of 42 living adults (age range, 30-45 years) who had the disease and by performing postmortem studies (anatomic and histologic) on the tracheas of older adolescents and young adults (age range, 15-33 years) who died with the disease. Anteroposterior tracheal diameters were enlarged in 41 of the living adults. The average diameter was 1.3 +/- 0.9 SD standard deviations above the mean for normal subjects. These increases did not correlate with severity of pulmonary disease as judged radiographically. Enlargement seemed to have developed slowly, over many years or decades. A few tracheas were grossly irregular in outline. One patient had a severely increased transverse diameter of 4.7 standard deviations above the normal mean. The average transverse diameter was 0.3 +/- 1.1 SD standard deviations above the normal mean. The tracheas of adults and older adolescents who had died with cystic fibrosis were abnormally flaccid. Some collapsed suddenly during deflation. Microscopic examination showed instances of severe inflammation, focal epithelial metaplasia, hypertrophy and hyperplasia of the mucous glands, degenerative changes in the muscle of the pars membranacea, and death of cartilage cells. The structural changes shown histologically and the many decades of frequent, vigorous coughing may be important in the enlargement of these tracheas and their flaccidity.