An Interesting Phenomenon of Bilateral Catamenial Pneumothorax Refractory to Hormonal and Surgical Interventions

Abstract Introduction: Catamenial pneumothoraxes are often associated with pulmonary migration of endometriosis, and treatment options are not well established. We present a case of recurrent bilateral catamenial pneumothoraxes refractory to both hormonal and surgical Interventions. Case: A 34-year-old woman with history of abdominal endometriosis (previously on leuprolide injections) initially presented with progressively worsening shortness of breath. Chest X-ray revealed right-sided tension pneumothorax. Video-assisted thoracoscopic surgery (VATS) along with lung biopsy resolved the pneumothorax, and pathology showed endometrial tissue along the pleura, diagnosing catamenial pneumothorax. She presented three months later with further respiratory distress. Chest X-ray and computed tomography (CT) thorax imaging showed large right-sided pneumothorax with significant air-fluid levels, right to left midline shift, and multiple irregular thick septations within the right pleural space. Even though treatment centered on menses suppression with hormonal therapy, she experienced recurrent hydropneumothoraxes requiring decortication and pleurodesis on the right side. Several years after the initial presentation, having discontinued leuprolide injections, she developed a new left apical pneumothorax (Figure 1), alongside stable right hydropneumothorax, complicated by respiratory distress requiring non-rebreather oxygenation. A chest tube placement resolved the right-sided pneumothorax. She was discharged with leuprolide injections and oral norethindrone daily outpatient. However, left-sided pneumothorax worsened, and the ectopic endometrial tissue size in the right-upper lobe increased. A left-side chest tube and VATS with pleurodesis were completed, but air-fluid levels of loculated right hydropneumothorax still persisted. Discussion: Thoracic endometriosis syndrome can present as catamenial hemoptysis, hemothorax, or pneumothorax. Catamenial pneumothorax presents as spontaneous pneumothorax, typically within 72 hours of menstruation, and typically favors the right thorax. Bilateral involvement, as observed in our patient, is rare and estimated to comprise 3% of cases. Many but not all patients are previously diagnosed with abdominal endometriosis. VATS allows for histopathological diagnosis and treatment with laser, resection of pleural and parenchymal implants, closure of diaphragmatic fenestrations, and mechanical or chemical pleurodesis. Post-operatively, hormonal therapy to suppress menses is crucial to lower the rate of recurrence. However, as seen in our patient, the risk of recurrence still remains. Even though surgical interventions and hormonal therapy were pursued at several instances, the extended period of time that she was not on hormonal therapy may have contributed to significant spread of endometrial lesions and worsening of bilateral pneumothoraxes. Conclusion: Catamenial pneumothorax is a dangerous condition. Therefore, early diagnosis along with surgical treatment and concurrent long-term menses suppression with hormonal therapy may reduce pneumothorax recurrence and morbidity.