Pleural mesothelioma is a type of cancer that develops in the lung's outer linings - the pleura.

Your mesothelium is a large covering of tissue that protects a number of your body's organs in both your abdominal cavity and your chest cavity. Your pleura is the two-layered membrane surrounding your lungs.

The inner layer of the pleura surrounds your lungs. The outer layer connects to the wall of your chest. The small space between the two is the pleural area.

Approximately 70% of all cases of malignant mesothelioma are pleural mesothelioma.

What Causes Pleural Mesothelioma?

Usually people absorb asbestos through inhalation. Once inhaled, there is no physiological process through which the human body can get rid of asbestos fibers.

The sharply edged asbestos fibers usually lodge themselves in the lungs and, over time, work their way to and embed themselves in the pleura. When this happens the fibers will cause the mesothelium cells to grow uncontrollably.

The walls of the pleural will thicken. This will cause fluids to build up. Eventually tumors will develop.

Because this process often takes decades, mesothelioma usually isn't diagnosed until many years after someone was exposed to asbestos. It's a slow process that can take twenty to forty years. But, eventually, it may cause symptomatic developments.

Once the mesothelium starts to swell, the space between the chest wall and the outer lung starts to narrow.

Until that time the body provides a thin layer of fluid between the surfaces. The fluid permits them to slide against each other.

However, the fluid dissipates because of the swelling. When that happens the mesothelioma victim feels acute discomfort with every breath because the surfaces of the now-dry walls rub against each other.

The opposite effect can be caused as well, and that's when excess fluid takes up the pleural space. This is called pleural effusion. The excess fluid makes it difficult to take in a full breath of air. If this happens excess fluid can initially be drained non-surgically. This will reduce the patient's discomfort.

Eventually, though, this condition will develop in eighty- to ninety-percent of pleural mesothelioma victims. Of those, about 60% feel the discomfort "only" on the right side of their chest cavity.

Pleural mesothelioma can be particularly difficult to treat using standard radiologic therapy and standard chemotherapy because it is a diffuse type of cancer. Because it consists of a lot of small tumors rather than one large tumor there isn't a single large mass that can be targeted.

If you or someone you love has (or had) mesothelioma then you may be entitled to a legal settlement.