Mediastinal window: a cause of simultaneous bilateral spontaneous pneumothorax

A case of bilateral spontaneous pneumothorax with critical collapse of both lungs in a previously healthy 19-year-old woman is described. A congenital defect of mediastinal septum was suspected on the basis of roentgenographic findings and confirmed by right-sided thoracotomy. This mediastinal window between the pleural spaces allowed air leaking from a ruptured right lung apical bulla to collapse not only the right lung but also the left. Apical TA stapler resection and right-sided parietal pleurectomy was performed to prevent recurrence.