Catamenial pneumothorax due to solitary localization of diaphragmatic endometriosis

Introduction: Catamenial pneumothorax (CP) is a spontaneous recurrent pneumothorax occurring in women in reproductive age. The etiology of CP has been associated with thoracic endometriosis and is its most common presentation. Presentation of case: A case of right catamenial pneumothorax in a 38 year old woman is presented in which three episodes of CP occurred within 72 h of menses in a 6 month period. The patient underwent videothoracoscopy that revealed a solitary localization of diaphragmatic endometriosis. After surgical pleurodesis and based on final pathology of resected lesion, hormonal treatment was started. The outcome was uneventful and the patients is symptom-free at 6 months. Discussion: Catamenial pneumothorax (CP) is a rare clinical entity characterized by lung collapse during menstruation, believed to be secondary to pleural endometriosis. Nearly all catamenial pneumothorax occur on the right side as pleural lesions are almost exclusively right-sided. Diagnostic imaging is based on high resolution computed tomography (HRCT) and, preferably, magnetic resonance imaging (MRI) since it is able to detect the blood products in the endometrial deposits. However the lack of macroscopic findings at surgery makes this condition still under-diagnosed. Based on the solitary diaphragmatic localization of endometriosis in our case we preferred to limit surgery to videothoracoscopic pleurodesis and start hormonal treatment with successful outcome. Conclusion: Catamenial pneumothorax is the most common presentation of thoracic endometriosis syndrome and should always be suspected in women in childbearing age. Treatment option are still debated but best results are achieved by videothoracoscopic pleurodesis combined with hormonal therapy