[Endometriosis as a cause of pneumothorax].

A young woman, who had formerly been diagnosed with endometriosis, was admitted to hospital with five incidents of right-sided spontaneous pneumothorax. Despite two thoracoscopic operations the pneumothorax reoccurred. The third operation revealed histologically verified endometriotic tissue of the diaphragm causing diaphragmatic fenestrations. It was concluded that the patient suffered from catamenial pneumothorax, where transdiaphragmatic passage of air from the cervix through the peritoneum during the menstruation period is believed to cause pneumothorax.