Spontaneous pneumothorax following partial resolution of total bronchial obstruction.

Spontaneous pneumothorax following chest irradiation is thought to occur in patients with radiation fibrosis several months or more after the completion of therapy. In the four patients presented herein, spontaneous pneumothorax was seen during or immediately after therapeutic radiation of lung cancer. All patients had bronchoscopic findings of bronchial obstruction by the tumor before treatment and radiographic improvement of atelectasis was observed during therapy. The interval between the improvement of atelectasis and the development of pneumothorax varied by less than three weeks. These common findings suggest that rupture of alveoli or emphysematous bullae and subsequent pneumothorax might be due to overinflation of the affected lung caused by partial bronchial obstruction. We should be aware of the occurrence of spontaneous pneumothorax following partial resolution of total bronchial obstruction.