Recurrent catamenial pneumothorax caused by diaphragmatic fenestration.

Catamenial pneumothorax, which is a rare cause of spontaneous pneumothorax, is defined as a pneumothorax that starts at the onset of or within the first 72 hours of the menstruation period in women.1 Catamenial pneumothorax was first described by Maurer et al in 1958.2 The reported incidence of catamenial pneumothorax among the spontaneous pneumothoraces is 3–6%, but the actual incidence is 25–30%, because catamenial pneumothorax is under-diagnosed.1,3-6 Although catamenial pneumothorax is clinically similar to the other primary spontaneous pneumothoraces, it is distinguished by being observed in women of reproductive age and by recurrence in menstrual periods. The pathophysiology of catamenial pneumothorax is uncertain. Thoracic endometriosis or subpleural endometrial implants seem to be the most realistic explanation. If thoracic endometriosis is not detected, diaphragmatic fenestrations should be considered. In that situation, air enters the peritoneal cavity through the genital tract during menstruation, then, passes into the right hemithorax through the fenestrations on that side of the diaphragm, and causes pneumothorax.4,5 We report a patient with catamenial pneumothorax who underwent repeated thoracotomy for recurrent pneumothorax, which revealed diaphragmatic fenestration during the operation. Case Summary