Mesothelioma is a cancer that arises from the cells lining the chest or abdominal cavities.

• 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.
• Health care professionals diagnose mesothelioma with a biopsy.
• The outlook for patients with mesothelioma depends on how early the disease is detected and how aggressively it is treated.
• Physicians often first detect mesothelioma late in the course of the disease, usually with a poor prognosis.

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 becoming apparent with symptoms in the chest area such as chest pain, cough, and/or shortness of breath. Shortness of breath often occurs due to a large pleural effusion (fluid in the thoracic cavity). Peritoneal mesothelioma is much less common. This can affect 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, also referred to as biphasic. 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. Surgery cures this so-called benign mesothelioma.