What is Mesothelioma?

Mesothelioma is a very rare type of cancer a rare form of carcinoma of the mesothelium lining lungs or abdomen or heart; usually associated with exposure to asbestos dust. When it develops, mesothelioma is almost always caused by asbestos.

There are two types:

Pleural Mesothelioma is a Cancer of the pleura, which is the membrane that lines the lungs and chest cavity.

Peritoneal Mesothelioma is a cancer of the peritoneum, which is the lining of the abdomen.

Mesothelioma, like other cancers, will not normally develop for many years after first exposure to asbestos. However, some people have developed mesothelioma merely from being around a worker's contaminated clothing.

What is Peritoneal Mesothelioma ?

Peritoneal Mesothelioma is a type of cancer that is found in the abdomen in a thin membrane called the peritoneum.

Symptoms include abdominal swelling, loss of appetite, and weakness. The only known cause to this disease is exposure to asbestos.

Due to the latency effect of this cancer, this exposure is likely to have taken place 20 or more years ago.

This type of mesothelioma is the less common and is found in less than 30% of all mesothelioma cases.

Pleural Mesothelioma

Pleural mesothelioma is a malignant mesothelioma that spreads within the chest cavity and sometimes involves the lung.

Asbestos exposure is the most common risk factor associated with mesothelioma. Asbestos refers to a family of magnesium-silicate mineral fibers that have been commonly used for insulation and in the shipbuilding and construction industries. A history of asbestos exposure is found in 80 percent of patients who present with mesothelioma. Other factors, which may promote mesothelioma, include: chronic lung infections, tuberculous pleuritis, radiation (Thorotrast) and exposure to the simian virus 40 (SV40) or mineral fibers (Zeolite). Although tobacco smoking has not been associated with the development of mesotheliomas, the combination of smoking and asbestos exposure greatly increases the risk of lung cancer.

In the United States, 2,000-3,000 patients are diagnosed with malignant pleural mesothelioma each year.
Mesothelioma affects men more frequently than women and is more common in white Americans.
The median age of onset of symptoms is 70.
Seven percent of workers exposed to asbestos become affected.
The latent period between exposure to asbestos and the onset of symptoms can be 20-40 years.
The median survival time is between 4-12 months, depending on the stage of presentation. The three-year survival is 10 percent and the overall five-year survival is approximately 5 percent.
The severity of the condition varies from person to person, but in most cases the onset of Pleural Mesothelioma is usually very slow with the most common presenting symptom being persistent pain localized in the chest. Sometimes the pain is accompanied by severe difficulty in breathing or shortness of breath. Cough, weight loss, fever and night sweats are less common.

TestingL Pleural mesothelioma is of two kinds:

1. diffuse and malignant (cancerous )

2. localized and benign (non-cancerous.)

Benign mesotheliomas can often be removed surgically, are generally not life-threatening, and are not usually related to asbestos exposure. Malignant mesotheliomas, however, are very serious. Fortunately, they are rare - about two thousand people are diagnosed with mesothelioma in the U.S. each year.

The remainder of this section is about diffuse malignant pleural mesothelioma.

Pleural mesothelioma is a cancer of the cells that make up the pleura or lining around the outside of the lungs and inside of the ribs. Its only known cause in the U.S. is previous exposure to asbestos fibers, including chrysotile, amosite or crocidolite. Exposure to these fibers within ten years of a diagnosis of this type of cancer can be considered as a likely contributing factor in the disease process. It is the most common type of mesothelioma, accounting for about 75% of all cases.

Mesothelioma is sometimes diagnosed by coincidence, before there are any symptoms. For instance, tumors have been discovered through routine chest x-rays. However, when symptoms occur, they may include shortness of breath, weakness, weight loss, loss of appetite, chest pains, lower back pains, persistent coughing, difficulty in swallowing, alone or in combination. An initial medical examination often shows a pleural effusion, which means an accumulation of fluid in the pleural space - the area between the lungs and the chest wall.

The first step in detecting pleural mesothelioma is, typically, a chest x-ray or CT scan. This is often followed by a bronchoscopy, using a viewing scope to look inside the lungs.

The actual diagnosis usually requires obtaining a piece of tissue through a biopsy. This could be a needle biopsy, an open biopsy, or through a tube with a camera (thoracoscopy or chest scope.) If an abnormality is seen through the camera then a tissue sample can be taken at the same time, using the same tube. This is a hospital procedure that requires anesthesia, but is not usually painful. The tissue sample is tested by a pathologist.

Fluid build-up from the pleural effusion can generally be seen on a chest x-ray and heard during a physical examination, but a firm diagnosis of mesothelioma can only be made through a biopsy and pathological testing. This is important because there are also benign pleural effusions and other tumors that have a similar appearance to mesothelioma. Diagnosing mesothelioma can be quite difficult; it requires special lab stains, and much experience in understanding them.

The spread of the tumor over the pleura causes pleural thickening. This can reduce the flexibility of the pleura and encase the lungs in an increasingly restrictive girdle. With the lungs restricted, they get smaller and less functional, and breathing becomes more difficult. At first a person with mesothelioma may be breathless only when he or she exercises, but as lung function drops, he or she can become short of breath even while resting.

The tumor spreads by direct invasion of surrounding tissue. As it spreads inward it can compress the lungs. As the tumor spreads outward it can invade the chest wall and ribs, and this can be extremely painful.

Current medical science does not know exactly how and why, at a cellular level, asbestos fibers cause mesothelial cells to become abnormal (malignant or cancerous.) Thus it is not known whether only one fiber causes the tumor or whether it takes many fibers. It seems that asbestos fibers in the pleura can start a tumor as well as promote its growth; the tumor does not depend on any other processes for its development.

There is as yet no known cure for malignant mesothelioma. The prognosis depends on various factors, including the size and stage of the tumor, the extent of the tumor, the cell type, and whether or not the tumor responds to treatment. The Firm has represented many clients who lived for five to ten years after diagnosis, most of them in good health for a majority of those years. Some mesothelioma victims succumb within a few months; the average survival time is about a year.

chest pain and pain in the lower back
difficulty breathing
coughing
weight loss
fever
muscle weakness and sensory loss
swelling of the face and arms
hoarseness
coughing up blood
Unfortunately, the early mesothelioma symptoms are often ignored or mistaken for minor ailments because they are not specific to the disease.

Therefore, it is critical to investigate one's exposure to asbestos. While pain in the lower back or at the side of the chest, shortness of breath, trouble swallowing, cough, fever, sweating, fatigue and weight loss may be common to many minor ailments, it is the knowledge that these mesothelioma symptoms are present in a person with a high likelihood of asbestos exposure that should raise a red flag.

Mesothelioma symptoms and signs from mesotheliomas depend upon location of the mesothelioma, its size and whether it is benign or malignant
Benign forms of the disease are generally asymptomatic
The symptomatology of malignant mesotheliomas is due to tumour growth resulting in invasion of surrounding structures and/or the production of fluid (pleural effusion, ascites, or pericardial effusion). Chest pain may be caused by invasion of the chest wall. Pleural effusion causes collapse of adjacent lung and shortness of breath
Mesothelioma symptoms of distant spread are possible, but uncommon since the tumour is usually a local problem and blood borne spread is uncommon
Patients with more advanced disease may be ill generally with fever, night sweats and weight loss
Involvement of the membrane around the heart (pericardium) may cause heart rhythm disturbances