Abstract
Catamenial pneumothorax (CP) is a rare form of spontaneous pneumothorax associated with thoracic endometriosis and is exceptionally uncommon in adolescents. We report a 14-year-old girl with early menarche and heavy menses who presented with abdominal pain and was incidentally found to have a right-sided pneumothorax. Despite chest tube drainage, video-assisted thoracoscopic surgery (VATS) with bleb resection and pleurectomy, and subsequent chemical pleurodesis, she experienced recurrent episodes temporally associated with menstruation. A second VATS identified new blebs without diaphragmatic fenestrations or endometriotic lesions. Pathology was negative for lymphangioleiomyomatosis, while estrogen and progesterone receptor stains were also negative, leaving the case without histologic confirmation. Ultimately, the strong temporal association with menses and sustained remission after complete menstrual suppression with oral contraceptives supported a clinical diagnosis of catamenial pneumothorax.