Catamenial pneumothorax is an extremely rare condition that affects women. Pneumothorax is the medical term for a collapsed lung, a condition in which air or gas is trapped in the space surrounding the lungs causing the lungs to collapse. Women with catamenial pneumothorax have recurrent episodes of pneumothorax that occur within 72 hours before or after the start of menstruation. The exact cause of catamenial pneumothorax is unknown and several theories have been proposed. Some cases are associated with the abnormal develop of endometrial tissue outside of the uterus (endometriosis), although the exact nature of this relationship in these cases is unknown.
The symptoms and severity of catamenial pneumothorax can vary from one episode to another and from one person to another. In the majority of affected women, the right lung is affected.
Symptoms that may occur with catamenial pneumothorax include monthly episodes of chest pain that can radiate to the shoulder blades, shortness of breath or difficulty breathing (dyspnea), dizziness, fatigue, and a dry cough. Some women have reported a “crackling” sound upon inhaling during an episode.
Chest pain associated with a collapsed lung is often severe and the condition often requires prompt medical attention.
The exact cause of catamenial pneumothorax is unknown. Several different theories have been proposed involving metastatic, hormonal and anatomical abnormalities. It is possible that catamenial pneumothorax may have different causes in different cases.
In the metastatic model, catamenial pneumothorax is caused by the abnormal migration of endometrial tissue from the lining of the uterus (endometrium) to other areas of the body such as the diaphragm or the space in between the membranes lining the chest cavity wall and the lungs (pleural space). When endometrial tissue is found outside of the uterus, the term endometriosis is used. Many women with catamenial pneumothorax have endometriosis. Endometriosis can cause small holes or openings (fenestrations) in the diaphragm, which would allow air and fluid to pass through into the pleural space. Many women with catamenial pneumothorax have endometrial tissue in the lungs, a condition called thoracic endometriosis. However, some women with catamenial pneumothorax do not have diaphragmatic fenestrations or endometrial tissue in the lungs suggesting that other factors may play a role in the development of the disorder or that other causes of the disorder (apart from endometriosis) exist.
In the hormonal model, researchers believe that a hormone known as prostaglandin F2, which is elevated during ovulation, causes narrowing (constriction) of the small tubes within the lungs (bronchioles). Bronchiolar narrowing may cause the small air sacs (alveoli) of the lungs to rupture, allowing air to become trapped in the pleural space.
In the anatomical model, researchers believe that the absence of the cervical mucous plug, a normal occurrence during the menstrual cycle, allows air to pass from the genital tract into the pleural space through small holes or openings (fenestrations) in the diaphragm.
Another theory that has been proposed as a cause of catamenial pneumothorax is the spontaneous ruptures of blebs. Blebs are small blisters or pustules that may be filled with fluid or air and can develop on the lungs. Some researchers speculate that hormonal changes during the menstrual cycle may cause blebs to rupture, which in turn can result in pneumothorax.
Catamenial pneumothorax affects women during their reproductive years, most often during their thirties or forties. The exact incidence of the disorder is unknown. Many researchers believe that catamenial pneumothorax often goes undiagnosed or misdiagnosed, making it difficult to determine its true frequency in the general population.
The term catamenial is derived from Greek and means “monthly”. The term catamenial pneumothorax was first used in the medical literature in 1972, although the disorder had been reported in the medical literature decades earlier.
A diagnosis of catamenial pneumothorax is made based upon a detailed patient history, a thorough clinical evaluation and identification of characteristic symptoms (i.e., repeated episodes of pneumothorax in conjunction with the onset of menses). A variety of tests may be required to rule out other conditions and to identify associated conditions such as thoracic or pelvic endometriosis or damage to the diaphragm. A minimally invasive procedure known as video-assisted thoracoscopy (VATS) may be used as a diagnostic aid. During a VATS procedure, a 1-cm rigid tube (thoracoscope) with a tiny, fiber-optic camera at the end is passed through a small incision in the chest. This allows physicians to examine the lungs, chest cavity and diaphragm.
An episode of pneumothorax may be treated with oxygen followed by observation and rest if the collapse is small. Serious episodes of pneumothorax may require the insertion of a chest tube to release trapped air and/or blood, thereby allowing the lungs to re-expand.
Both surgery and hormonal therapy, either separately or in combination, have been used to treat women with catamenial pneumothorax. No specific guidelines exist for the optimal treatment of catamenial pneumothorax. Specific therapies may depend upon the exact cause of pneumothorax, an individual’s age and general health, personal preference, and/or other factors.
Surgery may be performed to remove (excise) all suspected areas of endometrial tissue in the lungs and pleural space and to repair any damage or holes within the diaphragm. Surgery may also be used to remove small blisters located on the top of the lungs (apical blebs).
In addition, the artificial destruction of the pleural space (pleurodesis) may also be used to treat women with catamenial pneumothorax. Chemicals or drugs may be used to cause inflammation of the two layers of the pleura (i.e., the membrane lining the lungs and the wall of the chest cavity). This inflammation causes the pleurae to stick together (adhere) eliminating the pleural space. Another procedure, called pleural abrasion, can also be used to cause inflammation and adhesion of the pleurae. During pleural abrasion, the pleurae are inflamed through friction by wearing down or rubbing away (abrading) the pleurae.
Another surgical procedure that has been used to treat some affected women involves a mesh made from specialized material. During this procedure, a mesh is placed over the diaphragm in order to block any tiny holes that may have been missed during surgery. The mesh is absorbed over time and the resultant scar tissue eliminates any remaining holes in the diaphragm. This procedure is recommended even in women who have undergone pleurodesis or pleural abrasion.
Hormonal therapy may also be used to treat women with catamenial pneumothorax, usually as an adjunct to surgical therapy. Gonadotropin releasing hormone agonists are drugs that suppress ovulation and prevent the release of other hormones including estrogen or progesterone. These drugs are commonly used to treat women with endometriosis, but have been effective in some women with catamenial pneumothorax, even those who do not have signs of endometriosis.
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Mason RJ, Broaddus VC, Murray JF, Nadel JA. Eds. Murray and Nadel’s Textbook of Respiratory Medicine. 4th ed. Elsevier Saunders. Philadelphia, PA; 2005:2277-2278.
Simpson A, Skelly E. Catamenial pneumothorax. Emerg Med J. 2008;25:859.
Alifano M, Jablonski C, Kadiri H, et al. Catamenial and noncatamenial, endometriosis-related or nonendometriosis-related pneumothorax referred for surgery. Am J Respir Crit Care Med. 2007;176:1048-1053.
Leong AC, Coonar AS, Lang-Lazdunski L. Catamenial pneumothorax: surgical repair of the diaphragm and hormone treatment. Ann R Coll Surg Engl. 2006;88:547-549.
Peikert T, Gillespie DJ, Cassivi SD. Catamenial pneumothorax. Mayo Clin Proc. 2005;80:677-680.
Marshall MB, Ahmed Z, Kucharczuk JC, Kaiser LR, Shrager JB. Catamenial pneumothorax: optimal hormonal and surgical management. Eur J Cardiothorac Surg. 2005;27:662-666.
Alifano M, Roth T, Broet SC, et al. Catamenial pneumothorax: a prospective study. Chest. 2003;124:1004-1008.