Mesothelioma (cancer of the mesothelium) is a disease in which cells of the mesothelium become abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Cancer cells can also spread (metastasize) from their original site to other parts of the body. Most cases of mesothelioma begin in the pleura or peritoneum.

The mesothelium is a membrane that covers and protects most of the internal organs of the body. It is composed of two layers of cells: one layer immediately surrounds the organ; the other forms a sac around it. The mesothelium produces a lubricating fluid that is released between these layers, allowing moving organs (such as the beating heart and the expanding and contracting lungs) to glide easily against adjacent structures.

The mesothelium has different names, depending on its location in the body. The pleura is the membrane that surrounds the lungs and lines the wall of the chest cavity. The peritoneum is the mesothelial tissue that covers most of the organs in the abdominal cavity. The pericardium covers and protects the heart. The mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis. The tunica serosa uteri covers the internal reproductive organs in women.

The most prevalent form of this asbestos cancer is pleural mesothelioma, which arises in the pleura (the lining of the lungs and chest cavity). Peritoneal mesothelioma affects the lining of the abdominal wall, the peritoneum. Pericardial mesothelioma affects the pericardium, the lining of the heart.

These cancers mainly result due to exposure to asbestos. Typically the period of time between exposure to asbestos and visible onset of the disease is long. Thus many people who were exposed to asbestos decades ago are currently developing the disease. Opportunities to prevent these cancer illnesses were missed when the asbestos industry hid facts about the dangers of asbestos. Through numerous legal actions it has been proven that the asbestos industry was negligent for decades in hiding the serious dangers that result from asbestos exposure.

Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. About 3,000 new cases of mesothelioma are diagnosed in the United States each year. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age.

Source: PATHOLOGY OF ASBESTOS-RELATED DISEASES (Victor L. Roggli et al. eds., 2004)

Links

National Cancer Institute (NCI) Resources

Cancer Information Service (toll-free)

Telephone: 1–800–4–CANCER (1–800–422–6237)

TTY: 1–800–332–8615

Online

NCI’s Web site: http://www.cancer.gov
LiveHelp, NCI’s live online assistance:
https://cissecure.nci.nih.gov/livehelp/welcome.asp

]]> http://www.themesotheliomasociety.com/mesothelioma-asbestos-cancer-facts-and-figures/feed 0 http://www.themesotheliomasociety.com/asbestos-cancer-types-and-symptoms-information http://www.themesotheliomasociety.com/asbestos-cancer-types-and-symptoms-information#comments Mon, 02 Jun 2008 21:30:16 +0000 admin http://themesotheliomasociety.com/asbestos-cancer-types-and-symptoms-information/ Mesothelioma is a form of cancer that develops in the lining around the lungs (the “pleura”), abdomen (the “peritoneum”) or heart (the “pericardium”). Mesothelioma is almost always caused by exposure to asbestos. In contrast, lung cancer refers to a malignancy of the lung itself. There are three types of Mesothelioma.

Types of Mesothelioma

1. Pleural Mesothelioma

This type of cancer develops in the thin tissue lining that surrounds each of the lungs. The lining, called the pleura, is located inside the chest and completely encloses each of the lungs. In order to protect the lungs, the pleura produces a small amount of fluid. This fluid helps cushion the lungs, allowing them to move more smoothly during breathing

Non-cancerous pleural mesothelioma is a tumor that has not spread to other organs of the body. If the tumor is large, it may squeeze the lung itself and cause shortness of breath and pain.

Cancerous (malignant) pleural mesothelioma is due to the presence of a tumor that is cancerous and can spread to other parts of the body. This rare form of cancer is also found in the pleural sac lining that surrounds the lung. Exposure to asbestos is considered the primary cause of pleural mesothelioma.

Symptoms of pleural mesothelioma may include shortness of breath, chest pain, back pain, pain in the rib cage, fluid build-up in the lung lining, hoarseness, coughing up blood, swelling of the face and arms, muscle weakness, paralysis and loss of senses. These symptoms may be caused by mesothelioma or by other, less serious conditions. It is important to see a doctor about any of these symptoms. Only a doctor can make a diagnosis.

2. Peritoneal Mesothelioma

This type of cancer develops in the abdominal lining. One way doctors diagnose peritoneal mesothelioma is by looking inside the abdominal cavity with an instrument called a peritoneoscope. In this procedure, a cut is made through the abdomen wall and the peritoneoscope is placed into the abdomen. This test, called a peritoneoscopy, is usually performed in the hospital.

Some patients develop excessive fluid in the abdomen, called an effusion. A doctor may take a sample of the fluid to diagnose this type of cancer. Fluid in the abdomen might also be drained to relieve symptoms of peritoneal mesothelioma. The procedure for drawing out this fluid is called “paracentesis”.

The symptoms of this cancer may include stomach pain, weight loss, nausea, vomiting, hernia, fluid in the abdominal cavity or a mass in the abdomen. Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing or swelling of the neck or face. These symptoms may be caused by mesothelioma or by other, less serious conditions. It is important to see a doctor about any of these symptoms. Only a doctor can make a diagnosis.

3. Pericardial Mesothelioma

This is cancer of the sac that surrounds the heart. Your doctor may diagnose pericardial mesothelioma using a thoracoscope to perform a thoracoscopy, which might also involve opening up the chest cavity to remove the tumor.

Patients who develop excessive fluid around the heart, called an effusion, may have a sample of the fluid taken to diagnose pericardial mesothelioma.

Cell Types of Mesothelioma

A patient’s doctor or medical records may refer to the “cell type” of the malignant mesothelioma. This refers to the type of tissue where the cancer first developed. For example, “epithelial” malignant mesothelioma refers to cancerous cells that develop in the “epithelium,” which is the membrane lining of the lung, heart or abdomen. In contrast, “sarcomatous” malignant mesothelioma arises in connective tissue. “Biphasic” refers to malignant mesothelioma that arises in two different cell types. Other cell types of malignant mesothelioma are lymphohistiocytoid and desmoplastic.