Types of Mesothelioma

Many people think of mesothelioma as a disease of the lungs, but that is not always the case. Mesothelioma is a type of cancer that is generally caused by asbestos exposure. It can can be diagnosed in anyone who has been exposed to asbestos, even briefly, but is more common in those who were exposed to high levels of the toxic substance, or who worked around it for years. It can take 20 to 50 years after the exposure began for the individual to develop any mesothelioma symptoms.

Asbestos fibers are microscopic, sharp and easy to inhale. After being inhaled, these fibers can lodge in any area of the body that has a special protective lining, called a mesothelium. The mesothelium forms a double membrane which both lines the inner body cavities and covers the organs. The lungs, heart, stomach and testes are all protected by a mesothelial layer, and their natural movement is aided by the production of a special fluid produced by the mesothelium.

Pleural Mesothelioma

Pleural mesothelioma, which is one of the most common asbestos-related cancers, develops in the pleural mesothelium, the membrane that lines the lungs and the inside of the chest cavity. Pleural mesothelioma can be extremely difficult to diagnose, both because of its decades-long latency period, and because its symptoms tend to be non-specific. Shortness of breath, coughing, chest pain and fatigue are associated with a number of common respiratory conditions, including the common cold, emphysema, bronchitis and asthma. Occasionally, a patient experiencing these symptoms may feel that they are just getting over a mild virus, or even just getting older, and therefore avoid consulting their physician. When they do seek medical attention, the doctor may not suspect mesothelioma unless there is known asbestos exposure in the patient's past. Many cases of pleural mesothelioma are initially misdiagnosed.

Peritoneal Mesothelioma

Peritoneal mesothelioma is the second most common type of cancer caused by asbestos exposure. Doctors are not completely sure how the asbestos fibers make their way into the abdominal cavity, but one plausible explanation involves asbestos dust falling into the victim’s food or beverage, and then being ingested. Others have hypothesized that the fibers can travel through either the bloodstream or the lymphatic system after being inhaled. In any case, the fibers lodge themselves inside the abdominal lining and begin to develop tumors. Like pleural mesothelioma, peritoneal mesothelioma is very difficult to diagnose because of the range of non-specific symptoms that it can cause. Patients may experience pain, bloating and in some cases, shortness of breath.

Pericardial Mesothelioma

Pericardial mesothelioma is one of the rarest types of mesothelioma. Again, the genesis of this cancer is not precisely understood, but it is known the asbestos fibers can penetrate the pericardium, or the membrane around the heart, which then develops scar tissue as a result of constant invasion of these fibers. This scar tissue builds up, eventually interfering with normal heart function, in addition to fostering the formation of a cancerous tumor. Some symptoms of pericardial mesothelioma include an irregular heartbeat and heart palpitations, as well as chest pain and difficulty breathing.

Many cases of both peritoneal and pericardial mesothelioma are discovered only when the patient's physician is conducting screening or surgery for an unrelated condition.

Another form of mesothelioma involves the testicular lining. Testicular mesothelioma is the rarest form of mesothelioma, with under 100 confirmed diagnoses. Because this cancer is so rare, it is difficult to determine what the actual symptoms are. The most apparent include testicular lumps or swelling in the scrotum area. Doctors simply do not know how the asbestos fibers are absorbed into the testicular lining.

Mesothelioma is an aggressive cancer. Treatment may include surgery, chemotherapy and radiation, but they are less effective than in other types of cancer. Also, because the fibers are embedded in the body’s lining, the tumors will keep appearing and most likely become malignant. Another obstacle with mesothelioma is accurate and timely diagnosis. The latency period is so extensive, the fibers have had plenty of time to wreak havoc on the body’s lining before ever causing any symptoms.

Men have a much higher rate of mesothelioma than women. This can be attributed to the 27.5 million jobs, most of which were traditionally held by men, that dealt with asbestos during the 40-year span of its peak usage. Family members who lived with an asbestos worker are at higher-than-average risk of developing mesothelioma, as well, because asbestos fibers can be carried home on clothing.