The rare form of cancer, affecting the protective lining, called mesothelium, of most of the internal body organs is known as Mesothelioma. In most cases, this disease affects outer-lining of the lungs and the internal chest wall, whereas, it may also affect the lining of the abdominal cavity, along with affecting the heart, and the serous covering of the testis, called tunica vaginalis.

In this form of cancer, Mesothelioma, cancerous/malignant cells are found in the mesothelium, a protective membrane that covers most of the body's internal organs. In short, Mesothelioma is a cancer of the mesothelium. In order to understand this rare form of cancer, we first need to shed some light on what is mesothelium.

Mesothelium is a membrane which is covering and protecting most of the internal organs of the body. This membrane comprises two layers of cells- one layer directly surrounds the organ; whereas, the other forms a sac around it. A lubricating fluid is produced and released by the mesothelium between these layers, which allows the movement of organs, including beating of the heart, and the expanding and contracting of the lungs. This basically results in easy gliding of the organs against adjoining structures. There are various names of mesothelium, entirely based upon its position in the body. The peritoneum is the mesothelial tissue that covers most of the organs in the abdominal cavity. The pleura is the membrane surrounding the lungs and lining the wall of the chest cavity. The pericardium covers and protects the heart. The mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis, whereas in women, the tunica serosa uteri cover the internal reproductive organs.

Now, in the disease known as Mesothelioma, the cells of mesothelium become abnormal and segregate without control or order, invading and damaging nearby tissues and organs. Cancer cells can also spread from their original site to other parts of the body. Most cases of mesothelioma begin in the pleura or peritoneum. The chances of the occurrence of Mesothelioma are more common in men, than in women, and the risk of getting affecting by this increases with age. However, this disease can appear in either men or women at any age.

A person, who is more exposed to asbestos, silicate mineral with long, thin fibrous crystals, is more likely to get Mesothelioma, although, this disease has also been reported in some individuals without any known exposure to asbestos. In contrast to lung cancer, smoking does not appear to increase the risk of Mesothelioma, but the combination of smoking and asbestos exposure significantly increases a person's risk of developing cancer of the air passageways in the lung.

It is possible that the symptoms or signs of Mesothelioma may not appear until the person reaches the age of 30 to 50 years. Nevertheless, these signs and symptoms include shortness of breath; chest pain; weight loss; abdominal pain; and swelling due to a buildup of fluid in the abdomen. In addition to these, bowel obstruction, blood clotting abnormalities, anemia, and fever may also be experienced. 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.

If a person suspects that he/she has been affected by Mesothelioma, then he/she must consult a doctor immediately and should get the condition properly diagnosed. Mesothelioma can be diagnosed through a chest x-ray, CT scan, and biopsy. Once the diagnosis process is done, the treatment of Mesothelioma is then decided depending upon its location, that is, where the disease has occurred. The treatment also depends upon the stage of Mesothelioma, along with the patient's age and general health. The most common forms of treatment to this disease include surgery, chemotherapy, and also radiation therapy. There may be a few times when all these treatments might be combined.