Pericardial mesothelioma is extremely rare. It is caused by the embedding of needle-like asbestos fibers that become inserted into the lining of the heart. This results in damage to the pericardium, which is the sac around the heart.
Understanding Pericardial Mesothelioma
Only 200 cases of pericardial mesothelioma have been reported in medical journals, representing about 1 percent of all mesothelioma diagnoses.
There are two layers of the pericardium — the inner and the outer layer. Mesothelioma can be found in either one of these two layers. While it is generally considered that nearly all mesotheliomas are the result of exposure to asbestos, doctors and researchers are at a loss to explain how asbestos fibers are able to get from the outside of the body into the pericardial sac. Doctors recognize that asbestos fibers have the ability to migrate once inside the body, but it is unknown exactly how they reach as far as the pericardium.
Pericardial mesothelioma is twice as common in men when compared to women. This is thought to be because men are more likely to be exposed to asbestos in the workplace. Most people with this disease are 50-70 years of age when diagnosed, as it often takes several decades before the asbestos exposure develops into mesothelioma cancer. Pericardial mesothelioma is a difficult disease to diagnose because of its rarity, and because the symptoms are similar to those found in more common diseases.
Symptoms of Pericardial Mesothelioma
When the disease remains localized to the pericardium and the lesion is small, this type of cancer often exhibits no obvious symptoms. This is why it is rarely diagnosed in its early stages. When symptoms do occur, they are similar to those seen in heart disease. As a result, people are often misdiagnosed with some type of heart condition and the cancer isn’t discovered until later on.
The most recognized symptoms of pericardial mesothelioma are usually those that can be detected with visual imaging tests. The cancer can cause pericardial fluid to build up around the heart and this is often detected with an echocardiogram, x-rays, or a CT scan of the chest.
Typical symptoms seen in pericardial mesothelioma include:
- Dry cough
- New onset of a heart murmur
- Shortness of breath (with or without activity)
- Heart palpitations
- Chest pain
- Worsening of shortness of breath when lying down
- Night sweats
If you are exhibiting any of these symptoms, it is important to seek medical attention. These signs could indicate that you have fluid around your heart. If you know you have been exposed to asbestos, your symptoms could be a result of pericardial mesothelioma.
Causes of Pericardial Mesothelioma
Doctors and researchers have not yet found the exact cause of pericardial mesothelioma. However, based on the other forms of mesothelioma, asbestos exposure is the most likely cause of the disease.
It is difficult to conclude how inhaled asbestos particles can travel from the lungs (where they are inhaled) to the pericardial membrane (where they remain). As a result, the exact relationship between asbestos and pericardial mesothelioma is less clear than it is in more common kinds of mesothelioma.
Theoretically, it could be possible for asbestos fibers to travel from the lungs to the lining around the heart. The asbestos fibers embed into the lining around the heart, irritating the tissue. It can take several decades for the asbestos fibers to migrate to the pericardium and turn the tissues into cancerous cells.
After the pericardial cells mutate and turn into cancer, they divide quickly and form a mass around the heart. The cancer cells thicken the pericardial lining and fluid begins to build up in response to the irritation of the lining. This puts added stress on the heart, leading to heart-related symptoms.
Diagnosis of Pericardial Mesothelioma
It is not easy to diagnose pericardial mesothelioma. A doctor will likely listen to your symptoms and perform a physical exam. Imaging studies, such as an echocardiogram, chest x-ray or a CT scan may show thickening of the pericardium, along with fluid around the heart.
The doctor may then perform a procedure called a pericardiocentesis, in which a needle is inserted into the space between the heart and the pericardium. Fluid can then be drawn out, and sometimes cancer cells can be found when investigating this fluid under the microscope. In some cases, it takes a biopsy of the affected area to definitively make the diagnosis of pericardial mesothelioma.
Only about 10-20 percent of mesothelioma cases are diagnosed while the patient is still alive. The rest are found in an autopsy after the patient has already died of the disease. Besides a biopsy and fluid aspiration techniques, a radionuclide study using an injection of a radioactive dye can be performed, which may show evidence of the disease while the patient is still alive. The best test, however, is a CT scan of the chest, which will show the fluid around the heart and possibly the cancer itself.
Pericardial mesothelioma is often misdiagnosed as any of these other, more common, heart diseases:
- Coronary artery disease
- Tuberculosis of the pericardium
- Acute heart failure
- Intra-atrial myxoma
- Cardiac tamponade
- Weakness of the heart muscle
If you were diagnosed with any of the above conditions and you suspect it may be an incorrect diagnosis, you should seek a second opinion from a heart and lung specialist. They will be able to make sure the diagnosis isn’t something less common, such as pericardial mesothelioma.
Treatment of Pericardial Mesothelioma
Mesothelioma of the pericardium is difficult to treat because the cancer is located so close to the heart. The major treatments used to treat the disease include surgery to remove the visible signs of tumor, radiotherapy to shrink the size of the tumor, and chemotherapy to kill all tumor cells that weren’t removed by radiation and surgery.
Even with all three treatments methods, only about 50 percent of people diagnosed with pericardial mesothelioma survive past the six-month mark.