Spontaneous pneumothorax usually occurs abruptly without antecedent trauma to the chest. This diagnosis is subdivided into primary spontaneous pneumothorax, which occurs in healthy individuals without any known etiology, and secondary spontaneous pneumothorax, which is associated with underlying lung disease.
There are many etiologic lung diseases producing secondary spontaneous pneumothorax, which is rare in lung cancer as a complication. Moreover, the occurrence of spontaneous pneumothorax after chemotherapy is very rare.
The mechanism for development of spontaneous pneumothorax in primary or metastatic lung cancer has been described as a rupture of an emphysematous bulla in an overexpanded portion of lung partially obstructed by neoplasm, or an actual rupture of peripheral necrotic tumor into the pleural space.
And effective chemotherapy may increase the risk of spontaneous pneumothorax in patients with manifest or occult lung metastases by inducing rapid lysis of the tumor tissue and by interfering with repair process.
This report describes two cases of repeated spontaneous pneumothorax after chemotherapy in a patient with osteosarcoma and another patient with epithelioid sarcoma, and discusses possible pathophysiologic mechanisms.
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