Pericardial mesothelioma is an extremely rare form of malignant mesothelioma. Mesothelioma is a cancer of the mesothelium, the thin layer of cells that serves as a “wrapper” for the lungs, the heart, and the stomach and intestines. In pericardial mesothelioma, the tumors form in the mesothelium that surrounds the heart, the pericardium.
The pericardium is wrapped around the heart and the origin points of all the body’s major veins and arteries. The pericardium keeps the heart in place, stops it from expanding when it is under pressure, and provides lubrication for the heart’s beating motion. There are two layers to the pericardium, the visceral layer and the parietal layer. The visceral layer is inside, next to the heart, while the parietal layer is outside. Between the two layers is a fluid layer, called pericardial fluid. The parietal layer is tougher and stronger than the visceral layer; the two layers and the liquid insulating layer provide protection for the heart from damage to the chest.
The exact mechanism for developing pericardial mesothelioma is not known. Unlike pleural mesothelioma, in which asbestos fibers are inhaled and lodged in the lungs and eventually cause the cancer, there seems to be no direct route for asbestos fibers to enter the pericardium and cause mesothelioma. It is established that asbestos exposure is the primary cause for pericardial mesothelioma, however; what is not known is exactly how the asbestos reaches the heart. One possibility is that the smallest asbestos fibers might enter the bloodstream from the lungs, and be thus carried into the heart cavity.
Relatively little is known about pericardial mesothelioma because it is a fairly rare form of the disease; nearly all mesothelioma sufferers have pleural or peritoneal mesothelioma. Pericardial mesothelioma symptoms include difficulty in breathing, as a result of pressure mounting on the heart from the buildup of tumor mass. Pericardial mesothelioma causes a fluid buildup in the pericardium, which makes it more difficult for blood to flow into the heart and makes it hard for the ventricles to completely fill. This is called cardiac tamponade and the resulting symptoms can include an increased heart rate or an abnormal pulse, as the heart works harder to provide the body with blood flow. The fluid surrounding the heart and filling the pericardium is responsible for most of these symptoms and can cause pain in the heart area; for this reason, many sufferers of pericardial mesothelioma believe they are having a heart attack.
As with other forms of malignant mesothelioma, the prognosis for patients diagnosed with pericardial mesothelioma is grim. Although life expectancy statistics are generalizations to populations and there are always individual exceptions, most people diagnosed with pericardial mesothelioma die within a year of their diagnosis at most. There are no effective treatments for malignant mesothelioma, although medical researchers are always working to find new ways of fighting this terrible disease.