Primary lung cancer complicated with pneumothorax.

Eighteen lung cancer patients with a pneumothorax complication were studied. Pneumothorax appears rarely in lung cancer patients, having been found in 18 out of 5567 (0.32%) at our hospital over a period of ten years. Of the 18 patients, eight had adenocarcinoma, seven epidermoid carcinoma and three alveolar cell carcinoma. Unlike those of previous reports, our results showed pneumothorax not to be found exclusively on the same side as the lung cancer. It was contralateral in five cases. Pneumothorax was the initial manifestation of lung cancer in three cases and occurred as a complication in another 15. Of these 15 patients, 11 were described as developing pneumothorax between one and twelve months after completion of radiation therapy for lung cancer. Another two patients developed pneumothorax following cytotoxic chemotherapy. Pneumothorax occurred prior to any treatment for lung cancer in the remaining two patients. The factors contributing to pneumothorax in the lung cancer patients were the rupture of the necrotic neoplastic tissue into the pleural cavity, the rupture of a subpleural bleb or the formation of interstitial air due to partial bronchial obstruction by the tumor, complications arising from radiation therapy and cytotoxic chemotherapy, or any combination of such factors. Pneumothorax was an ominous sign for the lung cancer patients. Most (12/14) died within six months of the onset of pneumothorax.