Lung cysts are a manifestation of BHD syndrome. They are also called pulmonary cysts, lung blebs and bullae. The cysts are sacs in the lung tissue that are filled with air and so can be detected by radiological tests, such as an X-ray or a CT scan, which make the air visible.
While an initial scan can be helpful and verify if you have cysts, some experts do not consider regular CT monitoring necessary. Others however recommend a scan every few years, especially for those who experience symptoms. You may wish to speak to your lung specialist.
The cysts are prone to rupture at any time. The air from the ruptured bleb then enters the space in between the lung and the chest wall (called the pleural space) and creates pressure on the lungs. Consequently, part of the lung or the whole lung may collapse.
Changes in external air pressure may potentially be a cause of rupture. If you have lung cysts, it may be advisable to consider avoiding high altitudes, scuba diving, and flying in unpressurised aeroplanes. However, each individual’s body reacts differently to the surrounding environment and a recent study has shown that flying in aeroplanes is safe for most people affected by lung conditions like BHD. You may want to discuss air travel and other activities with your doctor.
Please see Spontaneous pneumothorax for more information regarding how to detect and deal with a suspected pneumothorax.
Lung cysts are a common manifestation of BHD; more than 80% of adults with BHD have the cysts. BHD lung cysts are most often located in the lower half (basal area) of the lungs. However, as with other manifestations of BHD syndrome, the presence, onset and quantity of lung cysts vary from family to family, and individual to individual. Some BHD families are hardly aware of their existence. While researchers do not yet clearly understand how cysts are formed, some have suggested that the cysts appear during lung development (up to a few years after birth) and then do not increase with age.
Currently, researchers are examining situations which increase the risk of spontaneous pneumothorax, such as the number and location of lung cysts, as well as investigating the symptoms produced by different BHD mutations.
Publication date: September 2012
Review date: September 2014