Catamenial Pneumothorax in a Patient with Endometriosis: A Case Report.

Pelvic pain is a common presentation to the emergency department (ED). For female patients, endometriosis can be difficult to diagnose and can have life-threatening complications if missed. In this case report, we present a case of a patient initially presenting to the ED with a few days of crampy lower abdominal pain. After initial imaging, she was found to have a large pelvic hematoma with concern for active extravasation and a large hemothorax. After further evaluation, she was suspected of having endometriosis leading to thoracic endometriosis and a catamenial pneumothorax. Although endometriosis is not typically an emergent diagnosis, the complications of significant endometrial tissue spread can cause life-threatening impacts. Clinicians should consider complications of endometriosis in females of menstruating age.