Mesothelioma: Pleural and Peritoneal (Symptoms, Causes & Treatment)

Mesothelioma is a form of cancer that is almost always caused by previous 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 chest cavity), but it may also occur in the peritoneum (the lining of the abdominal cavity) or the pericardium (a sac that surrounds the heart)

Symptoms of peritoneal mesothelioma include weight loss and cachexia, abdominal swelling and pain due to ascites (a buildup of fluid in the abdominal cavity). 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.

At the GP
Usually you begin by seeing Your family doctor who will examine you and ask about your general health. Your doctor will ask you about your symptoms. This will include what they are, when you get them and whether anything you do makes them better or worse.Your doctor will ask you to lie down for a physical examination. The doctor will feel the area where there is pain or swelling. It may feel tender, or it may be possible to feel a lump. Your doctor will listen to your chest, to see if there are any signs of fluid collecting. After your examination, your doctor may need to refer you to hospital for tests and X-rays. You may be referred directly to a specialist. Or your GP may send you to hospital for some tests first.

At the hospital
If you see a specialist, you will be asked about your medical history and symptoms. The specialist will then examine you by feeling the area that is painful or swollen. You may be asked to have blood tests to check your general health. Then your tests will be arranged in the out patients department. If your doctor suspects you may have mesothelioma, you may have quite a few tests. This is because it can be difficult to diagnose. Many of the usual tests used to diagnose lung disease prove negative when used to diagnose mesothelioma. You may have

X-rays
CT scan
Thoracoscopy (and biopsy of the pleura)
Fluid drainage (thoracocentesis or abdoparacentesis)
Of these tests, X-ray, CT scan and thoracoscopy are the most important for diagnosing mesothelioma. But of course, at this stage, your specialist doesn't know what's wrong. So, as mesothelioma can be difficult to diagnose you may have a range of tests.

X-ray
You will almost certainly be asked to have a chest X-ray or abdominal X-ray. A chest X-ray can show up fluid collecting around the lung. An abdominal X-ray may show up a swelling or fluid in the abdomen (tummy).

CT scan
This is a computerised scan using X-rays. You may be asked to have a CT scan of your chest or abdomen. A CT scan can show abnormal swellings in body organs or lymph nodes. You may be given an injection of dye called ‘contrast’ before the scan. This helps to make the scan clearer to read. .

Thoracoscopy
This is a small operation usually carried out by a specialist surgeon. It is done under a general anaesthetic. A small cut (incision) is made in your chest wall and a thoracoscope (a telescope like instrument with a video camera attached) is inserted through the hole. Using forceps the doctor can take a small sample (biopsy) of the pleura, the tissues which cover the lungs. This is then sent to a laboratory for testing to see if there are any cancer cells. This is sometimes the only certain way of finding out what's wrong because mesothelioma can be so difficult to diagnose. Other tests may not always show mesothelioma or may not be able to show whether the problem is mesothelioma or a different type of lung problem.

Fluid drainage
Many people with pleual mesothelioma have fluid around their lungs (a pleural effusion). People with peritoneal mesothelioma may have fluid in their abdominal cavity (peritoneal effusion). Fluid build up happens because cancer cells are irritating the pleura or peritoneum. Fluid in the plura can make it difficult to breathe. Fluid in the abdomen can make the abdomen feel swollen and tight and uncomfortable. If mesothelioma is the cause of the fluid build up, the fluid may contain cancer cells. To drain the fluid off, a needle is put into the chest or abdominal cavity and the fluid drained through a tube into a bag. A sample of the fluid will be sent to a laboratory for testing to see if contains cancer cells. Your doctor may call this 'thoracocentesis' or pleural aspiration if you are having fluid removed from your chest. If you are having fluid removed from your tummy (abdomen), you may hear your doctor call it an abdoparacentesis or peritoneal aspiration.

Difficulty with diagnosis
Mesothelioma can be difficult to diagnose. This is because there are many different types of cells that can make up a mesothelioma tumour. Sometimes it can be very difficult for a pathologist (doctor who looks at cells under a microscope) to decide if the cells or tissue taken from the lungs (pleura) or the abdomen (peritoneum) are a type of mesothelioma. These cells can often look very similar to other types of cancerous cells. For example, pleural mesothelioma can look like other types of lung cancer and peritoneal mesothelioma can look like some types of ovarian cancer. Also, many of the usual tests doctors use to diagnose lung disease prove negative when they use them to diagnose mesothelioma. For these reasons if your doctor suspects you may have mesothelioma, you may have quite a few tests so they can be sure of a correct diagnosis.

Surgery
Surgery is used to remove the cancer. Depending on how far the cancer has spread, the surgery may involve the removal of part of the lining of the chest or abdomen and some surrounding tissue. For cancer of the pleura (pleural mesothelioma), a lung may be removed, and in some cases the muscle below the lungs that helps with breathing (diaphragm), is also removed.

Radiation Therapy
Radiation therapy, also called radiotherapy, uses high-dose X-rays or other high-energy rays to destroy cancer cells. Radiation therapy affects cancer cells only in the treated area. The radiation may come from a machine or from radioactive materials placed directly in the area of the cancer (brachytherapy).

Chemotherapy
Chemotherapy involves the use of drugs to fight the cancer. Most drugs used to treat mesothelioma are intravenous (given by injection into a vein). Some doctors are also employing intracavitary chemotherapy -- putting chemotherapy directly into the chest or abdomen.