Regression of Large Lung Bullae after Peribullous Pneumonia or Spontaneously / 결핵및호흡기질환

ABSTRACT

BACKGROUND: A lung bulla may rarely shrink as a result of an inflammation within the bulla or a closing of a bronchus involved in the inflammation process, which is termed 'autobullectomy'. The purpose of this study was to describe clinical features of patients with regressions of bullae during follow-up. METHODS: We retrospectively reviewed the cases and individuals who showed unequivocal evidence of interval regressions in a pre-existing bulla. A total of 477 cases with a bulla >5 cm in diameter were screened manually. Thirty cases with bullae that showed regression during follow-up were selected. RESULTS: Regressions of large bullae occurred in 30 of 477 cases (6.3%). The median age of those patients was 61 (range, 53~66) years and 87% of those patients were men. The main cause of a bulla was emphysema (80%). Among 30 cases, 16 cases had pneumonia in the lung parenchyma of the peribullous area. Another 7 cases had a regressed bulla accompanied by an air-fluid level within the bulla. The remaining 7 cases showed a spontaneous regression of the bulla without such events. Complete regression of a bulla occurred in 25 cases. A follow-up chest-X ray showed that in all cases except one, the bulla remained in a collapsed state after 24 months. Forced expiratory volume in one second (FEV1) improved in 3 cases and the other 2 cases had increased forced vital capacity (FVC). In addition, total lung capacity (TLC) and residual volume (RV) decreased in another 2 cases. CONCLUSION: Regression of a lung bulla occurred not only after pneumonia or the presence of air-fluid level within the bulla, but also without such episodes. The clinical course of regression of a lung bulla varied. After regression of a bulla, lung function could be improved in some cases.