Catamenial pneumothorax is a rare condition characterized by a reoccurrence of air in the pleural space coinciding with the onset of menses.
Catamenial Pneumothorax is the most common form of thoracic endometriosis syndrome, which also includes catamenial hemothorax, catamenial hemoptysis, catamenial hemopneumothorax and endometriosis lung nodules, as well as some exceptional presentations. It is almost always right-sided, and generally affects women in their thirties and forties. Most physicians agree that endometriosis is involved. This condition is described as thoracic or pulmonary endometriosis.
More frequently however, articles describe cases involving diaphragmatic fenestrations (holes in the diaphragm). Endometriosis can attach to the lung, forming chocolate-like cysts. Generally the parietal pleura is involved, but the lung itself, the visceral layer, the diaphragm, and more rarely the tracheobronchial tree may also be afflicted. The cysts can release blood; the endometrial cyst "menstruates" in the lung. Air can move in by an unknown mechanism. The blood and air cause the lung to collapse. PSP typically occurs in tall, thin males aged 10-30 years. PSP rarely occurs in persons older than 40 years.
The recurrence rate in women receiving hormone treatment is 50% at 1 year. Pneumothorax is a medical emergency. Surgery, hormonal treatments and combined approaches have all been proposed, with variable results in terms of short and long term outcome. Surgical removal of the endometrial tissue should be endeavoured during menstruation for optimal visualisation of the cyst. Pleurodesis may also be helpful. Menstruation and accompanying lung collapse can be suppressed with hormone therapy, like with Lupron Depot, danazol or oral contraceptives. Polyglactin mesh to prevent catamenial pneumothorax.
