Spontaneous pneumothorax complicating lung metastases from carcinoma of the breast.

Spontaneous pneumothorax is an uncommon complication of lung metastatic disease. In most of the cases reported until today, the primary disease was a sarcoma (osteogenic sarcoma, soft tissue sarcoma, hemangioendotheliosarcoma, and Ewing's sarcoma). An exceptional case of spontaneous pneumothorax in a patient suffering from carcinoma of the breast with lung metastases, is herein presented. The pneumothorax developed immediately after regression of lung metastases during administration of combined chemotherapy. Some etiological factors, as well as the rarity of this complication and its treatment, are also discussed.