Catamenial Pneumothorax Caused by Diaphragmatic Endometriosis

Catamenial pneumothorax is a rare disease. The etiology and pathogenesis of this syndrome has remained enigmatic. Many hypotheses have been proposed including anatomical, physiological, and metastatic models. Each hypothesis has been criticized because of a lack of a unifying source for each report in the literature. We report a 39-year-old woman presenting with monthly right thoracic pain occurring before menstruation. Thoracic endometriosis was confirmed histologically after a thoracotomy with biopsy.