What is Catamenial Pneumothorax?

Catamenial pneumothorax is a rare condition that can afflict women just before or during their menstrual periods. The pleural tissue surrounding one of the lungs ruptures, leading to pressure buildup in the chest that ultimately causes lung collapse. Most specialists believe that catamenial pneumothorax is the result of endometriosis, a condition in which cells in the pleural lining react to menstruation similarly to uterine cells: rupturing and bleeding during a period. Surgery is usually necessary to repair a collapsed lung, and a patient may be given medications and hormonal supplements to help prevent recurring episodes.

Endometriosis in areas near the uterus is a fairly common condition, with uterine-like cells usually emerging in the long intestine, ovaries, or bladder. It is extremely rare for such cells to appear elsewhere, especially in the lungs. Doctors do not fully understand how or why the abnormal cells emerge. When they are present in the lungs and activated by menstruation, they can form cysts that swell and bleed. Inflamed cysts can open and leak air from the lung into the pleural lining and chest cavity. Within about 72 hours of a rupture, it is likely that the lung will collapse.

Catamenial pneumothorax can potentially afflict any woman of reproductive age who has not yet reached menopause. It is most common in individuals between the ages of 30 and 40. A woman who experiences catamenial pneumothorax is likely to first notice shortness of breath that worsens over time. She might have sharp pains in the chest, a rapid heart rate, and low blood pressure, symptoms that bring on fatigue and dizziness. Without prompt treatment, she can lose consciousness or stop breathing altogether.

Emergency care is necessary to identify and treat a collapsed lung. If the patient is stable, doctors can take chest x-rays and blood tests to determine the location of cysts and confirm that air has indeed escaped the lung. A tissue biopsy and hormone tests can be performed to determine whether or not symptoms are related to endometriosis.

A woman who is brought to the emergency room in critical condition typically needs surgical intervention right away to preserve breathing. A chest tube is inserted to remove excess air and blood. Once the space is cleared, damaged lung tissue can be repaired with surgical stitches and glues. Surrounding tissue that has not yet ruptured but appears suspicious is excised.

Following emergency treatment, doctors can initiate a course of medical therapy to prevent catamenial pneumothorax from recurring. Many women are instructed to take daily oral contraceptives to suppress menstruation. Hormonal therapy, involving medications or injections, can be given to reduce the risk of endometriosis. Most women who suffer from catamenial pneumothorax are able to avoid future episodes by taking their medications and scheduling regular checkups with their doctors.