Five cases of asymptomatic spontaneous pneumothorax.

Asymptomatic spontaneous pneumothorax (ASPT) is an uncommon condition. Between January 1, 1989 and December 31, 1997, 269 patients were admitted to our department with spontaneous pneumothorax. Of the 269 patients, 5 had no symptoms at the time of discovery. Their ages ranged from 15 to 61 years (mean, 37.8 years), and all of them were male. Of the 5 patients with no complaints, 2 had bilateral metachronous pneumothoraces and 3 had hemilateral pneumothorax. All of these ASPTs were revealed by chest roentgenographs taken during medical examinations or follow-up studies relating to other diseases. The mean value of body mass index (BMI) was 19.96 +/- 1.4 (range 18.7 - 22.1). Two of the 5 patients underwent bilateral partial lung resection. Histopathological examination of the resected specimens showed elastofibrosis, scar formation, and an interruption of the elastic fiber of the pleura. In these 5 cases, clinical courses were uneventful, and relapse of the pneumothorax did not occur. Clinical physicians should be aware of the possibility of asymptomatic pneumothorax, as well as the optimal radiographic techniques for revealing small pneumothoraces.