Facts About Pericardial Mesothelioma
Pericardial mesothelioma is a primary cancer of the pericardium, the layer of tissue that surrounds the heart. Because of this location, it is tough to treat. Pericardial mesothelioma is also very rare.
Pericardial mesothelioma is so rare that the exact number of cases is unknown. Some estimates put it at only 200 reported diagnoses ever. One study reviewed the medical literature and found only twenty-seven instances of pericardial mesothelioma between 1972 and 1992.[2] This accounts for about 1% of all known cases of mesothelioma.
Mesothelioma is a cancer of the mesothelium, the tissue that surrounds most organs in the body. The vast majority of cases are primary cancers of the pleura, the part of the mesothelium surrounding the lungs, because asbestos fibers are generally inhaled during exposure.
Peritoneal mesothelioma, cancer of the tissue surrounding abdominal organs, is the second most common.
The third most common is pericardial mesothelioma. The pericardium is a thin tissue made up of two layers. The inner layer is called the visceral layer or the epicardium, and the outer layer is called the parietal layer or the heart sac.[3] Tumors may begin growing in either or both layers.
What Causes Pericardial Mesothelioma?
Because pericardial cancer is so rare, studies are limited, and it is difficult to determine what causes it. Like pleural mesothelioma, causes are thought to include asbestos exposure. There may be a component of environmental or genetic factors.
Having a family history of this cancer and being exposed to asbestos over a long period of time are the two strongest risk factors. Men are twice as likely as women to have this type of cancer, likely due to workplace asbestos exposure.[4]
Pericardial mesothelioma, like pleural mesothelioma, is linked to asbestos exposure, but the connection is not as strong. It is not clear how asbestos fibers could get to the pericardium and cause a primary tumor. It may be that fibers migrate from lung tissue to the area around the heart.
Rates of asbestos exposure among people diagnosed with pericardial mesothelioma are much lower than those with pleural or peritoneal mesothelioma. Limited studies of people with pericardial mesothelioma have estimated that only about 15 to 30% of people getting the diagnosis were ever exposed to asbestos, as far as they knew.[4]
Symptoms of Pericardial Mesothelioma
As with other types of mesothelioma symptoms, pericardial mesothelioma has a long latency period, and symptoms often don’t appear until decades after any asbestos exposure.
In those cases with no asbestos exposure, symptoms still don’t seem to be troubling until the cancer has developed into later stages. Many symptoms of this type of mesothelioma result from the fact that it causes fluid to build up between the two layers of the pericardium and from a thickening of this tissue.
Potential symptoms of pericardial mesothelioma include:[5]
- Heart palpitations
- Trouble breathing
- Weight loss
- Shortness of breath when lying down
- Chest pain
- Fatigue
- Cough (often dry and non-productive)
- Night sweats
- Fever
Complications of Pericardial Mesothelioma
Pericardial mesothelioma can also lead to complications related to the heart. These do not indicate mesothelioma, as they can occur in many other situations, but they can be additional clues for the right diagnosis.
Pericardial Effusion
Pericardial effusion is the buildup of fluid between the two layers of the pericardium around the heart. It causes shortness of breath, pain, and a feeling of pressure in the chest.
Doctors can perform a pericardiocentesis to remove the fluid as a palliative measure. This involves inserting a thin needle into the pericardium and then using a catheter to drain it.
Heart Failure
Pericardial mesothelioma can also cause heart failure. This occurs when the heart can no longer pump enough blood for the body to use. This results in edema or fluid buildup in the body. Heart failure is progressive and incurable. It is a common cause of death in pericardial mesothelioma patients.[6]
Diagnosis of Pericardial Mesothelioma
The symptoms and the rarity of pericardial mesothelioma make it challenging to diagnose. The symptoms are often nonspecific and are caused by the fluid and thickening in the pericardium, both of which can be caused by other, more common conditions.[4][7]
- Physical Examination. A diagnosis will begin with a physical examination and medical history. Your doctor will want to know about your symptoms, past illnesses, and, if they suspect mesothelioma, your work history.
- Ultrasound. The next step is most likely an image of the heart, usually by ultrasound, called an echocardiogram, which can show fluid in the pericardium. Pericardial effusion is often a complication of pericardial mesothelioma, but there are other causes, too.
- Radionuclide Imaging. This type of imaging helps find suspected tumors around the heart. This involves injecting the patient with a radioactive element, which is transported into rapidly dividing cells, like cancer cells. A radiologist can then see by detecting radiation the location of tumors in the body. Doctors may also order a CT or computed tomography scan. This shows details of soft tissue and is one of the best ways to identify tumors.
- Biopsy. The last step in a diagnosis is a biopsy of the pericardium. Often, even if the fluid is drained from around the heart, there will not be enough cancer cells to provide a diagnosis. A biopsy is the removal of a small amount of tissue from the area of the tumor that a pathologist will examine under microscopy. The pathologist looks for abnormal cells to determine if the abnormal tissue is a malignant tumor. Even with this diagnostic tool, getting a firm answer is difficult.
Do I Need a Second Opinion?
All types of mesothelioma are difficult to diagnose. Because of its rarity, pericardial mesothelioma is especially challenging. Doctors are more likely to conclude your symptoms result from a more common condition, like:
- Heart disease
- Constrictive pericarditis
- Cardiomyopathy
- Cardiac tamponade
- Tuberculosis pericarditis
If you aren’t comfortable with your diagnosis, or you feel your doctor isn’t taking you seriously, get a second opinion. Consider seeking out a mesothelioma specialist.
Treatment
Treatment for any type of mesothelioma is challenging, but this is especially true for pericardial mesothelioma. A surgery called a pericardiectomy is one possible option and involves removing the pericardium, either in part or completely.[8]
In the early stages of cancer, this may cure it, but in most cases, the cancer is too far advanced, which will only prolong the patient’s life a little. It can also provide some relief from the pressure of the fluid buildup.
Chemotherapy and radiation treatment are standard treatments for other types of cancer. Radiation is not considered useful for extending life expectancy in patients with pericardial mesothelioma. Chemotherapy with surgery provides the most benefits for extending survival time.[9]
For most patients, the focus is not on a cure but on improving symptoms. Treatment most often involves palliative care to make the patient more comfortable.[9] Removing fluid and parts of the pericardium, for instance, relieve pressure on the heart and reduce pain and other symptoms.
What Is the Prognosis for Pericardial Mesothelioma?
The overall prognosis for pericardial mesothelioma is very poor, with median survival at less than six months from diagnosis.[9] Treatment often involves palliative care to make the patient more comfortable. Removing fluid and parts of the pericardium, for instance, relieves pressure on the heart and reduces pain and other symptoms.
If you know or suspect you had past exposure to asbestos, talk to your doctor about it. Take symptoms seriously and get screened as soon as possible for the best outcome.
