C45-15 Recurrent Massive Bilateral Catamenial Hemothoraces With Buffalo Chest Syndrome

Abstract Thoracic endometriosis syndrome (TES), a rare disorder characterized by the presence of functional endometrial tissue within the thoracic cavity, commonly presenting as catamenial pneumothorax (80%), followed by hemothorax (14%), hemoptysis (5%), and lung nodules. Up to 80% of affected women have concurrent pelvic endometriosis. Theories include retrograde menstruation, coelomic metaplasia, lymphatic and hematogenous dissemination, and prostaglandin-mediated mechanisms. In patients with catamenial hemothorax, the right hemithorax is typically involved, bilateral disease is exceptionally uncommon, as shown in this unique case. A 45-year-old lady presented with progressive dyspnea and generalized weakness for three days, denying orthopnea, melena, or urinary complaints. Her history includes thoracic and abdominal endometriosis, initially presenting in her 20s with a massive right pleural effusion causing severe mediastinal compression requiring thoracotomy, decortication, drainage, and a pleural biopsy confirming endometriosis. Since that, she has experienced recurrent pleural effusions and ascites requiring drainage every 2-4 months. On examination, she was pale and tachycardic, with decreased breath sounds in the right lower lung. Her hemoglobin was 7.4 g/dL. CXR revealed extensive bilateral lung opacities while CT angiography revealed multiple loculated right-sided pleural fluid collections along with lung compression and extension to the left lung. Abdominal imaging showed a large pelvic mass with ascites. MRI identified as uterine leiomyomas. She underwent a therapeutic thoracentesis, draining 2 L of serosanguinous fluid. Paracentesis removed 2160 mL of sanguineous ascitic fluid. Given her prior thoracotomy with decortication and stable status, VATS was deferred. Her bilateral pleural effusions improved after drainage from the right site, likely due to a buffalo chest syndrome. Management included a levonorgestrel IUD for hormonal suppression. She has previously failed Depo-Lupron and combined hormonal contraceptives. Options for GnRH therapy, and surgical treatment including hysterectomy with bilateral oophorectomy, abdominal myomectomy were discussed. Follow up with thoracic surgery and a multidisciplinary endometriosis center was arranged. TES predominately affects women aged 20-40s. Diagnosis relies on recognition of cyclical menstrual-related symptoms with radiologic features. While the right hemithorax is most commonly affected, our case uniquely demonstrates bilateral involvement, likely influenced by a mediastinal buffalo configuration permitting cross-mediastinal communication. Management typically includes combined VATS or thoracotomy along with hormonal therapy. The definitive treatment remains hysterectomy with bilateral salpingo-oophorectomy. TES remains diagnostically and therapeutically challenging due to its rarity, underrecognized menstrual correlation, and high recurrence rates despite surgery. This underscores the importance of clinical awareness and multidisciplinary collaboration in ensuring timely diagnosis and optimizing outcomes in these patients. This abstract is funded by: None