Multi-Loculated Catamenial Pneumothorax: A Rare Complication of Thoracic Endometriosis

The presence of endometrial tissue outside the uterine cavity is known as endometriosis. Catamenial pneumothorax (CP) is a recurrent spontaneous pneumothorax that occurs in women of childbearing age. Thoracic endometriosis is a rare clinical entity, and CP is the most common presentation. Imaging diagnosis is based on computed tomography (CT) scans and magnetic resonance imaging (MRI), detecting blood products in endometrial deposits. We report a case of right CP in a 37-year-old woman with chest pain and dyspnea 48 hours after the onset of menstruation. The pneumothorax was drained, continuous hormonal therapy was started, and she underwent video-assisted thoracoscopic surgery (VATS), which revealed multiple diaphragmatic fenestrations and a solitary nodular thickening in the diaphragmatic pleura (endometrial deposit). After pleurodesis, multiple CP recurred, and later underwent a total hysterectomy. CP is the most common form of thoracic endometriosis and should be suspected in women of childbearing age.