When Menstruation Meets the Pleura: A Rare Case of Catamenial Hemothorax and Thoracic Endometriosis and a Literature Review.

Catamenial hemothorax is a rare manifestation of thoracic endometriosis, characterized by blood in the pleural cavity associated with menstrual cycles. We present the case of a 42-year-old woman with recurrent right-sided chest pain and dyspnea coinciding with menstruation. Imaging revealed a large pleural effusion and hemothorax. Diagnostic video-assisted thoracoscopic surgery (VATS) confirmed thoracic endometriosis. The patient received a combination of hormonal therapy and VATS. Follow-ups over 36 months showed significant symptom improvement and resolution of pleural effusion. This case emphasizes the need to consider thoracic endometriosis in women with menstrual-related hemothorax.