[Clinical studies in five cases of Swyer-James syndrome].

We encountered five patients with Swyer-James syndrome. All were men, and ranged in age from 20 to 70 years (mean, 41 years). Their chest X-ray films showed left unilateral hyperlucency. Examinations revealed bilateral involvement in 3 cases and irregularity of involved regions in 2 cases. Chest CT scans revealed the distribution and severity of affected regions in greater detail than did other radiologic exams. Delayed clearance of xenon is a sign of air trapping, which is characteristics of this syndrome. Thus, 133Xe inhalation scintigrams were useful to detect air trapping, especially when mediastinal shift was not apparent on chest X-ray films. Bronchial damage is believed to cause this syndrome, and the present findings support this view. It is noteworthy that all five of these patients were men, and that in all five the affected lung was on the left. Moreover, although "respiratory tract infection is considered to be a very important" factor, many patients had no history of airway infection in childhood. Thus, some congenital factor or factors may contribute to the development of this syndrome.