[Diaphragmatic endometriosis-associated pneumothorax triggered by abortion; report of a case].

The patient was a 36-year-old woman. She had previously undergone surgery for hysteromyoma and endometriosis. At 8 week of pregnancy, the fetus's heart stopped beating, and the woman underwent abortion. On the same day, she began experiencing difficulty in breathing in the evening. After 4 days, she was referred to our hospital with dyspnea. Chest X-ray finding showed a right pneumothorax. Tube toracotomy was performed, and the right lung re-expanded immediately. Two months later, pneumothorax recurred without any association with the menstruation cycle. Thoracoscopic surgery was performed. No lesion was detected in the lung or visceral pleura, but a small hole and some thinned areas were noted in the diaphragm. Partial resection of the diaphragm was performed. Microscopic examination revealed endometriosis and localized lymphocyte infiltration in the resected diaphragm. It was suggested that the recurrence of pneumothorax without menstruation was caused by the thinning of the diaphragm due to endometriosis.