Monday, April 20, 2009

Peritoneal Mesothelioma:

Peritoneal mesothelioma is a disease that affects the lining of the abdomen, or peritoneum. Sometimes doctors refer to this disease as mesothelioma of the peritoneum. It is a common misconception that mesothelioma is a type of primary lung cancer; it is not. Mesothelioma is a cancer of the serous membranes. These membranes enclose a number of organs throughout the midsection of the body, including the abdomen. The most common type of mesothelioma is pleural mesothelioma, which affects the serous membranes of the lungs.

The second most common form of mesothelioma cancer is peritoneal mesothelioma. Peritoneal mesothelioma can spread to the lungs and when this occurs, it is considered secondary lung cancer. Mesothelioma is also sometimes referred to as an asbestos lung cancer. Technically, this is also incorrect, since it does not originate in the lungs. Asbestosis is a type of asbestos lung disease that does originate in the lungs and is often confused with mesothelioma.Peritoneal Mesothelioma Cancer

Peritoneal mesothelioma cancer is found in 10% to 20% of the mesothelioma patients. The only known cause of mesothelioma is exposure to asbestos. For pleural mesothelioma (cancer of the lung lining), the disease process is fairly well understood. It is caused by the inhalation of asbestos fibers that settle in the lungs. These asbestos fibers become inserted in the lung lining (or pleura). Asbestos fibers are very durable and cannot be eliminated through the body's processes. Over time, they cause chronic inflammation that eventually leads to growth of cancerous tumors or in some cases asbestosis.

For peritoneal mesothelioma, it is not clearly understood how the asbestos fibers become lodged in the abdomen's peritoneum lining. It is possible that asbestos fibers, after being broken into smaller pieces in the lungs, are carried from the lungs into the blood stream, and lodge from the blood stream in the abdomen lining.

A more probable cause is that asbestos fibers were ingested with food or drink. Most asbestos mining or processing facilities had constant clouds of asbestos fibers. These fibers could have settled on the food of the workers. Also, it is well established that many of the workers' clothing became infiltrated with asbestos dust. This dust could have contaminated the kitchens of the workers as they arrived home with the dirty clothing. Once lodged in the peritoneum, the chronic inflammation process leading to cancerous growths is similar to that occurring in pleural mesothelioma.

Mesothelioma of the Testicles

A rare form of peritoneal mesothelioma affects the male testicles. The covering layer of the scrotum is actually an outpouching of the peritoneum. It is thought that the asbestos fibers migrate from the stomach area to become lodged in the portion of the peritoneum surrounding the scrotum.

Peritoneal Mesothelioma Symptoms

Once the cancerous tumors start to grow in the peritoneum, fluid begins to rapidly accumulate in the abdominal area. This fluid causes swelling and discomfort and leads to the first common symptoms of peritoneal mesothelioma: upper abdominal pain. Less common symptoms include cough and shortness of breath. Many patients have symptoms four to six months before diagnosis.

Peritoneal mesothelioma patients can exhibit all three kinds of mesothelioma cancer cells: epithelioid mesothelioma, sarcomatoid mesothelioma and biphasic mesothelioma. The type of cancer cells can affect the prognosis. It is thought that patients with biphasic mesothelioma cancer cells have a shorter life expectancy, than that for epithelioid or sarcomatoid.

Introduction to Malignant Mesothelioma

Malignant mesothelioma affects the lining or membranes of certain large cavities in the body. These cavities, called the serous cavities, house certain major organs in the body including the heart, lungs, abdomen and others. The membranes that surround these cavities are called the serous membranes. They serve to protect these major organs from the friction and abrasion that occur as the organs move against each other during typical daily functioning, such as breathing and heart beating. The serous membranes derive from specialized cells called mesothelial cells. These cells form to create the mesothelium, which is the major tissue layer of the serous membranes. Cancer that occurs in the mesothelium tissue is called mesothelioma.

Malignant mesothelioma takes on three forms:
  • Peritoneal mesothelioma, in the peritoneum or membrane surrounding the abdomen. A rare form of peritoneal mesothelioma can also affect the male testicles, because the lining around the scrotum is an extension of the peritoneum.
  • Pericardial mesothelioma, in the perdicardium or lining surrounding the heart.
  • Pleural mesothelioma, which is the most common form of malignant mesothelioma and affects the lining of the lung cavity.

All mesotheliomas are now considered to be malignant, or cancerous. They start as a localized tumor and spread rapidly to include most of the surrounding tissues and organs. Originally, fibrous cists and other non-cancerous growths that appeared in the serous membranes were thought to be mesotheliomas and were termed "benign fibrous mesothelioma" and "multicystic mesothelioma." These conditions are now known not to originate in the mesothelial cells, but other cells within the serous membranes. These conditions are typically localized, non-cancerous and do not spread rapidly.

Etiology of Malignant Mesothelioma

Most cases of malignant mesothelioma are associated with a previous exposure to fibrous minerals, of which asbestos is the most important. There is now indisputable evidence of the role of these fibers in the development of this disease. This has been demonstrated in animal experiments and many other experiments. Not everyone who is exposed to asbestos fibers has developed malignant mesothelioma, suggesting that other factors may also be involved.
Although malignant mesothelioma is rare, it is a serious, deadly disease. It is often in the advanced stages when it is detected, so the outlook for the patients is not as good as it is for the cancers that are detected earlier. The average survival time after detection is 1 to 2 years. This survival time also depends on the type of mesothelioma.

Further Malignant Mesothelioma Information

Please continue reading the articles on this website for more mesothelioma information and asbestos information