Thursday, November 20, 2008

Mesothelioma: How Do Doctors Diagnose Asbestos Cancer? Part 1

As we discussed in our previous article, you might have been exposed to asbestos airborne particles if you have been building ships, working with heat insulation and changing old brakes pads. There are many dangerous occupations exist, such as, asbestos plant workers, automobile mechanics, boiler workers, plumbers, drywall workers, electricians insulators, painters, even hairdressers and teachers. Many other professions might give an occasional exposure to the asbestos particles.

As the consequence of asbestos exposure you may get asbestosis, but you may also start do develop mesothelioma - relativity rare but deadly type o cancer.

So, how do doctors diagnose the mesothelioma?

When you see your doctor, the first think he does to suspect the mesothelioma is asking about your occupational history. The paramount importance is to catch the asbestos cancer in the early stages of the disease, so time is of the essence. The survival rate is eight to twelve months on average. However, catching and treating the mesothelioma early at some cancer centers gives better results.

Doctors look for signs and symptoms of the cancer. The mesothelioma symptoms often delay up to 20 and more years after asbestos exposure. Yet, in rats intra-pleural introduction of asbestos chrysotile fibers may cause mesothelioma in several months.

People with mesothelioma complain on breath shortness, persistent cough, sputum, and chest pain. The pain comes from pleura - the lungs lining that is very sensitive to irritation. Mesothelioma tends to cause fluid accumulation in the pleural cavity.

Peritoneal mesothelioma causes weight loss, pain and ascites (belly swelling due to fluid in the abdominal cavity). Peritoneal mesothelioma also may block bowels and cause all kinds of troubles with gut obstruction. As many cancers, asbestos cancer also changes blood clotting, causes blood cells decrease (anemia), night sweats, and fevers. Ascites may lead to nausea and feet swelling. Spreading of the cancer will bring pain, difficult swallowing, and neck swelling. This symptom happens because of compression of some great veins going to the heart in your chest. In general mesothelioma symptoms are not very specific. They may characterize any other type of cancer as well as many other non-cancerous diseases. This problem delays diagnosis. Sometimes patients think that they have viral pneumonia. Some patients don't have any symptoms at all. Mesothelioma in advanced stage, as well as majority of cancers, will cause fatigue.

An x-ray may show a fluid accumulation.

What is a pleural effusion? Pleural effusion means the accumulation of fluid between the pleura on inside chest wall and diaphragm and pleura covering lungs. What is pleura? Pleura is the thin layer of special cells covering the lung and inside of the chest wall. It has an idea of closed plastic bag with some small amount of fluid inside. Basically, this bag helps lungs to slide easily against chest wall during expansion from breathing. The membranes of pleura consist from mesothelial cells. Exactly these cells produce a small amount of the lubricant. The amount of fluid is always in balance. Extra pleural fluid is quickly reabsorbed. When there is too much fluid, it is the effusion. Abdominal cavity has similar lining named peritoneum, which covers abdominal organs the way pleura covers the lungs. Mesothelioma leads to fluid build up, which is caused by cancer cells irritating the pleura or peritoneum. This fluid leads to sickness in your abdomen or difficulty breathing.

Transudation is a pleural effusion with clear fluid. It usually results from imbalance of fluid production and removal. It is more characteristic for some other disease. Doctors would think first about congestive heart failure. Mesothelioma would rather cause an exudate. Exudates are a cloudy pleural effusion with many cells and proteins. Exudates happen after the pleura is irritated and inflamed, as it happen in mesothelioma. To check the type of effusion, doctors would stick a needle and get the fluid sample. This stick is called diagnostic thoracentesis. The fluid will be checked in the lab. If mesothelioma is the cause, cancer cells may be found in the fluid

Why shortness of breath develops? The dyspnea (breath shortness) happens exactly because too much fluid is accumulated and press on the lung, pushing it away form the chest wall inside and thus making the lung smaller. Also the pain from inflamed pleura prevents patient from deep breathing. The receptors in inflamed pleura also cause dry cough. Listening to the lungs with a stethoscope reveals decreased breath sounds. Tapping on the chest sounds dull. This all is the consequence of fluid accumulation.

During your doctor's visit, you should discuss your concerns about asbestos exposure in the past. Your doctor should check the area of pain and swelling; he also should listen to your breath sounds and check for fluid collection. If your doctors suspect the effusion he may send you for tests and X-rays or refer to a specialist.

If a doctor suspects mesothelioma, he dose not have many specific tests on hands. Many of the usual tests may show no results in mesothelioma. Simple chest x-ray does not always show small pleural effusion. A lateral decubitus film may be required for smaller effusions (the same x-ray but the side view). Otherwise CT scan or ultrasound may show the effusion.

Aleksandr Kavokin, MD, PhD. Medical Articles http://www.kavokin.com, Free On-line diagnostics at http://www.symptomat.com, http://www.rdoctor.com

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