本文收集肺癌合并自发性气胸4例,鳞癌2例,腺癌2例。分析其发病机制为:①癌肿结节形成活瓣,造成支气管腔不完全阻塞,远端肺泡过度膨胀,撕裂肺泡壁,空气沿小叶间隔渗至胸膜下形成大疱,破入胸膜腔。②癌肿完全堵塞支气管,引起肺不张,邻近肺组织代偿性肺气肿,气肿疱破裂 This article collected 4 cases of lung cancer with spontaneous pneumothorax, 2 cases of squamous cell carcinoma and 2 cases of adenocarcinoma. Analysis of its pathogenesis: 1 cancerous nodules formed flap, resulting in incomplete bronchial obstruction, excessive expansion of the distal alveolar, alveolar tear walls, air leaks along the lobular interval to the pleura under the formation of bullae, broke into the pleural cavity. 2 cancer completely blocked the bronchus, causing atelectasis, adjacent pulmonary emphysema, emphysema rupture