Mesothelioma

• Mesothelioma is a cancer that arises from the cells lining the chest or abdominal cavities.
• Mesothelioma typically results from exposure to asbestos.
• When mesothelioma affects the chest, the doctor may look inside the chest cavity with a special instrument called a thoracoscope.
• When mesothelioma affects the abdomen, the doctor may look inside the abdomen with a special tool called a peritoneoscope.
• Mesothelioma is diagnosed by a biopsy.
• The outlook for patients with mesothelioma depends on how early the disease is detected and how aggressively it is treated.

Mesothelioma is a rare form of cancer (malignancy) that most frequently arises from the cells lining the sacs of the chest (the pleura) or the abdomen (the peritoneum). Pleural mesothelioma is the most common form, often presenting with symptoms in the chest area. Peritoneal mesothelioma is much less common. This can effect the organs in the abdomen, and its symptoms are related to this area of the body, that is, abdominal swelling, nausea, vomiting, and bowel obstruction. The rarest form of mesothelioma is pericardial mesothelioma, which involves the sac surrounding the heart.

There are two major cell types of mesothelioma, epithelial and sarcomatoid. Sometimes both of these cell types can be present. The sarcomatoid type is rarer and occurs in only about 15% of cases; it portends a poorer prognosis. In very rare cases, mesothelioma can originate from benign, non-malignant cells. This so-called benign mesothelioma can be cured surgically.

Most people present with complaints of shortness of breath. They also can have complaints of chest pain. Surprisingly, this pain is often not pleuritic; that is, it does not get worse with deep breathing. This is surprising in that the pleura (outer surface of the lung) is often involved in this disease, and most other diseases involving the pleura are often associated with pleuritic pain (pain that worsens with deep breathing). Patients may also be asymptomatic, with the disease discovered by physical exam or an abnormal chest X-ray.

As the disease progresses, shortness of breath increases, and weight loss, decreased appetite, and night sweats can develop. Local invasion by the tumor can result in changing of voice, loss of function of the diaphragm, and symptoms specific to the area and involvement of adjacent structures.

Source: MedicineNet.com
http://www.medicinenet.com/mesothelioma/article.htm