Pleural disease, which encompasses many different conditions, affects the health and function of the lungs. Although pleural disease does not actually, at first, infect the lungs themselves, it does damage the lining of the lungs, called pleura, and impair lung function.
The pleura are the membranes that line the chest wall and provide a lubricated, friction-free surface for the lungs to expand and contract against. When the pleura become damaged the amount of lubrication secreted either increases or decreases depending on the nature of the disease. This change in fluid secretion can cause increased pressure in the chest cavity, impaired or difficult breathing, inflammation of the lungs, and the development of other, more serious lung conditions.
Pleural disease is most commonly characterized by scarring of the pleura tissue. This scarring can be caused by different methods depending on the type of pleural disease that is present in the body.
There are four main types of pleural disease – pneumothorax, pleural effusions, pleurisy and pleural mesothelioma.
Pneumothorax is a condition characterized by the escape of air from the lung into the pleural space, or space between the outside of the lung and the inside of the chest cavity. When air is allowed to enter this space it interferes with the suction function of pleura, which keeps the lung inflated and results in a collapse of the lung.
Pleurisy is a condition that is caused by inflammation of the pleura. Pleurisy can be caused by viral infections, pneumonia, the presence of tumors, and blood clots in the lung. Sharp pains in the chest that worsen during deep breathing and coughing usually accompany pleurisy.
Scarring & Damage from asbestos
Pleural mesothelioma is an asbestos cancer of the pleura that is caused by asbestos exposure. This type of cancer accounts for almost two-thirds of all malignant mesothelioma cases. The inhalation of asbestos fibers can cause chronic inflammation in the pleural lining. This inflammation eventually leads to the abnormal division and growth of pleura cells and the eventual formation of cancerous tumors.
Exposure to, along with the inhalation of asbestos fibers can also lead to many other asbestos-related pleural disease. asbestosis is characterized by pleural scarring that is brought on by asbestos dust exposure. Pleural plaques, small areas of scarring, are usually not serious or symptomatic, but as they calcify, harden, and increase in size they can lead to chest pain and difficulty breathing.
Pleural thickening is the term used to describe large areas of scarring in the pleura that is brought on by asbestos exposure. This condition can also be non-symptomatic but as the scars enlarge many individuals experience extreme shortness of breath and difficulty breathing.
Rounded telectasis results from a rare form of pleural scarring, which causes portions of the affected lung to fold in on itself. This asbestos-related pleural disease leads to severe pain and difficult breathing.
All asbestos related pleural disease share a long latency period. The symptoms or complications of these diseases can take decades to present themselves. Most patients who present with signs of these conditions have had a long and significant history of asbestos exposure. Unfortunately, aside from measures to prolong life and relive pain, these conditions are usually untreatable and incurable.
Finally, the most common type of pleural disease is pleural effusion. This condition is characterized by an abnormal accumulation of fluid in the pleural cavity. When the pleural lining is scarred by disease or asbestos exposure it can allow the buildup of fluid in the space between the chest wall and the lungs.
There are two main types of pleural effusions – transudative and exudative. Transudative effusions are caused by a problem with the normal pressure level in the lung. The most common type of this effusion is congestive heart failure.
Exudative effusions are caused by a disease process in the lung. The most common diseases that lead to exudative effusions are tuberculosis, lung infections, asbestosis, and other asbestos-related pleural diseases.
While most pleural effusions are not symptomatic the symptoms of this condition can include chest pain, dry cough, and dyspnea (shortness of breath). These pleural effusion symptoms are not usually caused by the effusion itself, but rather by other underlying diseases and conditions.
Since most pleural diseases progress over time without any noticeable symptoms their diagnosis can be difficult and delayed significantly. The two most common diagnostic tools used to detect pleural disease are chest x-rays and chest CT scans. Chest radiography is very effective at pinpointing pleural effusion and is used to recognize fluid buildup in the chest cavity. CT (computed tomography) can also be used to detect pleural masses.
Other types of diagnostic tools used to detect pleural disease include ultrasound, pleural biopsy, and thoracoscopy. Ultrasound tests can help doctors differentiate between solid masses and liquid masses in the lungs, helping with the diagnosis of effusions. Pleural biopsies are used to extract and analyze the fluid in the pleural lining for disease and other markers. Finally, thoracoscopy is the preferred method for analysis because it offers doctors a video-assisted view of the pleura, a sample of the affected tissue, and a way to dissect masses all in one method of examination.
Once a diagnosis of pleural disease has been confirmed treatment can be considered. Depending upon the type of pleural disease different options are available for disease maintenance and symptom relief.
For symptomatic pleural effusions pleurodesis is a common choice of treatment. This technique is used to create inflammation in the pleural space, which leads to a reduction of space available for fluid accumulation.
Surgery to remove part of the pleura can also be used for treatment or symptom relief. This procedure is most commonly used in the cases of pleural mesothelioma and pleural effusions.
Although most cases of pleural disease do not require treatment and on their own are not cause for great concern, long-term progression of the disease can lead to further complications. Individuals with a history of asbestos exposure should see their doctor for regular physicals. Untreated and unmonitored pleural disease can set the stage for pleural and/or other types of mesothelioma as well as other life-threatening diseases.