Pericardial mesothelioma is a rare form of cancer found in the pericardium, a thin layer of smooth tissue that surrounds the heart.
Key Points about Pericardial Mesothelioma
- Pericardial mesothelioma is the rarest form of asbestos-caused cancer.
- Tumors first form in the lining of the heart (pericardium).
- In most cases, pericardial mesothelioma is not diagnosed until an autopsy is performed.
- Although it has the worst prognosis of all types of mesothelioma, there are some treatment options.
What is Pericardial Mesothelioma?
Primary malignant pericardial mesothelioma is one of the rarest forms of mesothelioma. Only 1 – 2 percent of all cases of mesothelioma originate in the pericardium, the two mesothelial layers surrounding the heart. These layers create a small cavity that allows the heart to expand and contract smoothly in the chest.
The cancer forms between the two layers of mesothelium. First the tissues start to thicken, reducing its ability to aid free movement of the heart. Fluid begins to build (this is called a pericardial effusion), and eventually tumors start to grow, further preventing the proper beating of the heart.
Many external factors come into play when making a prognosis, but generally, only 50% of people diagnosed with pericardial mesothelioma live another 6 months, and according to research, only one person has lived 5 years after diagnosis.
Pericardial mesothelioma can be primary or the result of mesothelioma metastasizing from other parts of the body and forming tumors around the heart. Males are twice as likely to have the disease as women, and most cases are only diagnosed during an autopsy.
- Cause // Asbestos inhalation or ingestion
- Location // Heart lining (pericardium)
- Common Symptoms // Chest pain
Pericardial effusion (fluid buildup)
- Treatment // Surgery
- Prognosis // 6 months
Pericardial Mesothelioma Linked to Asbestos
Like other forms of mesothelioma, there is a strong connection with asbestos exposure. A recent study states that at least 80% of all patients diagnosed with pericardial mesothelioma know they have come into contact with asbestos.
What is not known is the actual mechanics of how the asbestos reaches the pericardium to cause the cancer. Medical examiners find asbestos fibers in the pericardial lining in a small percentage of autopsies, but researchers are still unsure of how asbestos seems to have the high correlation that it does.
What are the Symptoms of Pericardial Mesothelioma?
Malignant pericardial mesothelioma is often misdiagnosed due to the similarity of symptoms with other heart conditions. This means most people are diagnosed after the cancer has had time to progress, leaving the patient too frail to live through the necessary surgery.
Pericardial mesothelioma has nonspecific symptoms which can be caused by other heart conditions. These conditions could be other cancers, non-cancerous diseases, or even inflammation, called pericarditis. Many of the symptoms listed below would also be present for these conditions.
These are some of the reported symptoms of pericardial mesothelioma:
- Shortness of breath
- Progressive shortness of breath
- Nonradiating chest pain
- Heart murmurs
- Fluid buildup around the heart (pericardial effusion)
- Distended jugular veins
- Accentuated variance in the pulse during respiration (Paradoxical Pulse)
- Swelling in the limbs
- Thickening of the pericardium
The extent of these symptoms will be determined by the stage of the cancer and the age of the patient.
Cancer caught at an earlier stage will not have created a heightened constrictive environment for the heart, and therefore the breathing, fatigue, and vascular stress of the patient will be less pronounced. The easier it is for the heart to beat, the less symptoms the patient will have.
When the patient is older, other symptoms like reduced muscle mass (muscular dystrophy) have been documented for the torso and arms.
How is Pericardial Mesothelioma Diagnosed?
Primary malignant pericardial mesothelioma can be very difficult to diagnose. There is a host of cancers that can appear similar with most means of imaging, plus the symptoms can also appear to be non-cancerous diseases. Further complicating the matter, only about 150 cases of PMPM have been documented in the medical literature.
A short list of diagnoses to rule out (“differential diagnoses”) appear below:
- Metastatic tumors
- Tuberculous pericarditis
- Rheumatic fever
- Cardiac myxoma
Many patients are misdiagnosed with one of the above diseases or conditions, with a true diagnosis being found at the autopsy. Only 30% of patients are correctly diagnosed with pericardial mesothelioma prior to death.
When assessing a patient with the above symptoms, a doctor would begin with a medical history and physical assessment. If the level of symptoms warranted further investigation, then the doctor would continue with imaging.
Ultrasound, CT, x-ray, and MRI can all be used to investigate where the chest constriction is coming from and what may be causing it. These tests can reveal inflammation of the pericardium, tumors, and/or pericardial effusion. These are non-invasive, painless tests.
A key factor in proper diagnosis is when doctors run tests on any pericardial effusions (fluid buildup in the pericardium) shown in the imaging.
The common linchpin for diagnosis is a biopsy of the tumor itself. This is done during surgery or autopsy..
Because the prognosis of the disease is so dependent on early treatment, a correct diagnosis is key.
How is Pericardial Mesothelioma Treated?
Prior to deciding on a treatment plan, the doctors will assess the prognosis of the patient. If it is believed the patient will survive greater than 12 months, then more aggressive treatments will be pursued. But if the patient’s symptoms and cancer have progressed, then the best treatment is whatever makes the patient most comfortable.
The following list presents many of the most common treatments. Surgical treatments are typically part of an aggressive regimen for those who have a better prognosis.
Pericardiectomy: This surgery removes some or all of the pericardium. Not only will this remove the tumor, but depending on stage, it will also remove many of the cancerous cells, preventing them from growing.
Pericardiocentesis: A large needle is inserted into the pericardium and fluid is removed, thus relieving the pressure on the heart.
Percutaneous Balloon Pericardiotomy: Patients with pericardial effusions from cancer are much more likely to require follow-up pericardiocentesis than those with fluid build-up due to non-cancerous reasons. This procedure uses a balloon to push the two layers of pericardium apart, allowing for greater fluid removal. This treatment will delay a subsequent pericardiocentesis.
Cisplatin: As with other forms of mesothelioma, Cisplatin is the chemotherapy of choice for treating pericardial mesothelioma. Chemo is frequently used with other medications or surgeries to form “multimodal treatment.”
While the research is somewhat split, radiation is not typically used as a primary treatment for pericardial mesothelioma, but radioactive isotopes are occasionally used in connection with surgery.
Photodynamic Therapy: Surgeons use a drug that causes heightened sensitivity to certain wavelengths of light. When the tumors are exposed to this light, it produces oxygen that kills the surrounding tissue.
Immunotherapy: Doctors will genetically alter some of the patient’s immune cells to attack the cancer tumor after they are re-introduced to the patient.