Mesothelioma is a rare form of cancer. It affects different parts of themesothelium, a membrane that covers and protects most of the body's internal organs. Depending upon the organ it covers and protects, the mesothelium has different names and the forms of mesothelioma are named after those different membranes.
For example, the mesothelial tissue, or membrane, surrounding the lungs and lining the wall of the chest cavity is called the pleura. Cancer of this membrane is called pleural mesothelioma.
Your heart is covered by the pericardium. Cancer of that membrane is called pericardial mesothelioma.
The membrane surrounding most of the organs in the abdominal cavity is known as the peritoneum, so cancer of that membrane is called peritoneal mesothelioma.
No matter which organs of the body it covers, the mesothelium is made up of two layers of cells. The first layer closely surrounds each organ. The second layer forms a sac around it. Between these two layers, the mesothelium produces a lubricating fluid which allows the surrounded organs to move easily. This lubrication allows our lungs to expand and contract effortlessly as we breathe in and out. It also lets our heart beat smoothly.
Pleural mesothelioma
Pleural mesothelioma is caused by malignant (cancerous) tumors which form in the lining of the membrane surrounding the lungs and the chest cavity. Fluid often builds up between the lining of the lung and the chest cavity. This is known as pleural effusion, which often causes shortness of breath and pain.
Pleural mesothelioma is by far the most common form of malignant mesothelioma. Like all forms of mesothelioma, those who've been exposed to asbestos for long periods of time - generally by working with or around asbestos or by living near mines or factories where asbestos was processed - are the most likely to develop this type of asbestos mesothelioma. However, family members who inhaled dust bought home on workers' clothes and people with brief exposures to asbestos can also develop this and other forms of malignant mesothelioma. In all types of mesothelioma, it takes anywhere from 10 to more than 50 years for symptoms to develop.
Symptoms of pleural mesothelioma can resemble pneumonia and other less serious diseases, so it's important to tell a doctor if you've been exposed to asbestos. Symptoms include shortness of breath, constant cough, or chest pain.
Although there is a form of mesothelioma in which benign (non-cancerous) tumors form in the pleura, nearly all cases of pleural mesothelioma aremalignant (cancerous).
Peritoneal mesothelioma
Peritoneal mesothelioma, which attacks the tissue surrounding the abdominal area, is much less common than pleural mesothelioma, but it is also caused by breathing in asbestos dust and fibers.
Symptoms of peritoneal mesothelioma can include weight loss, abdominal pain and swelling, bowel obstruction, blood clotting abnormalities, anemia, and fever. Just like pleural mesothelioma, the symptoms of peritoneal mesothelioma are similar to those of other less serious conditions or different diseases, which can make it hard to detect, especially if your doctor doesn't know that you've been exposed to asbestos.
Pericardial mesothelioma
Pericardial mesothelioma is an extremely rare form of asbestos mesothelioma. Many of the symptoms are similar to those of pleural mesothelioma: a constant cough, shortness of breath, or chest pain. Palpitations are another symptom. As with the other forms of mesothelioma, these symptoms are similar to those of other diseases, so tell your doctor if you've been exposed to asbestos.
In all forms of mesothelioma, as with other forms of cancer, the cancer cells can metastasize (spread) from their original site to other parts of the body, leading to other types of cancer.
Even with treatment, the outlook for most people diagnosed with mesothelioma is about 18 months after diagnosis, although some patients have lived for four or more years after diagnosis and treatment. Untreated, the prognosis is often as little as four months.
Until recently, treatment options have been limited, but awareness of the disease and continued research, including clinical trials of new treatments, mean that the outlook for survival is starting to look better.
