Catamenial pneumothorax: A rare cause of chest pain in the emergency department

Catamenial pneumothorax (CP) is defined as recurrent spontaneous pneumothorax occurring within 72 hours before or after onset of menstruation. The aetiology of this syndrome is unknown, although many theories have been proposed to explain it. A 43-year-old female presented to our emergency room with a complaint of left sided chest pain. She had no dyspnoea or haemoptysis during the admission. She had a history of pelvic endometriosis without any complaints for three years. Pneumothorax or pneumonia was not detected on chest X-ray. Blood tests and electrocardiogram findings did not support any cardiac or infectious cause. Computed tomography showed a pneumothorax on the mediastinal side of left hemithorax. The patient was referred to a thoracic surgeon. A thoracoscopy for histological confirmation was performed and the diagnosis of CP was made with a histological intervention.