Peritoneal Mesothelioma (Abdominal Mesothelioma)

Malignant peritoneal mesotheliomaAbdominal cavity showing the location of the peritoneum; peritoneal mesothelioma. is an extremely rare condition. Only 100 to 500 cases are diagnosed in the US each year, making up less than 30% of all mesothelioma cases.

Peritoneal mesothelioma is a cancer affecting the abdominal lining, or peritoneum (paira-tin-e-um), which is why is is sometimes referred to as abdominal mesothelioma. This membrane supports and covers the organs of the abdomen.

The peritoneum is made of two parts, the visceral and parietal peritoneum. The visceral peritoneum covers the internal organs and makes up most of the outer layer of the intestinal tract. Covering the abdominal cavity is the parietal peritoneum.

Cells in these linings secrete a fluid which allows organs to move against one another. For instance, as the intestines move food through the body. The cells of the mesothelium are designed to create fluid, but the cancer causes them to overproduce, creating a build up of excess fluid in the abdominal cavity.

Because pleural mesothelioma is more common and often spreads to the peritoneal cavity, it is important to determine if pleural mesothelioma is the primary cancer.

Mesothelioma

Mesothelioma is a form of cancer that is almost always caused by exposure to asbestos. In this disease, malignant cells develop in the mesothelium, a protective lining that covers most of the body's internal organs. Its most common site is the pleura (outer lining of the lungs and internal chest wall), but it may also occur in the peritoneum (the lining of the abdominal cavity), the heart,[1] the pericardium (a sac that surrounds the heart) or tunica vaginalis.

Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or they have been exposed to asbestos dust and fiber in other ways. Washing the clothes of a family member who worked with asbestos can also put a person at risk for developing mesothelioma.[2] Unlike lung cancer, there is no association between mesothelioma and smoking, but smoking greatly increases risk of other asbestos induced cancer.[3] Compensation via asbestos funds or lawsuits is an important issue in mesothelioma (see asbestos and the law).

The symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall) or chest wall pain, and general symptoms such as weight loss. The diagnosis may be suspected with chest X-ray and CT scan, and is confirmed with a biopsy (tissue sample) and microscopic examination. A thoracoscopy (inserting a tube with a camera into the chest) can be used to take biopsies. It allows the introduction of substances such as talc to obliterate the pleural space (called pleurodesis), which prevents more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy, radiation therapy or sometimes surgery, the disease carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing.