The only known cause of mesothelioma is asbestos exposure. Hundreds of thousands of American workers were exposed to asbestos products on the job during the twentieth century. Asbestos products were taken off the market in the United States, for the most part, by 1980; but prior to that time asbestos was a highly popular and widely used mineral incorporated into construction, industrial and manufacturing products – and into some consumer products as well. Asbestos insulation could be found in millions of American homes and in every ship the Navy commissioned from 1930 to about 1975. It was used in cement, wallboard, joint compound flooring, roofing, adhesives, auto and truck brakes, and hundreds of other products.
Workers who were around asbestos products that were worn or deteriorating or that were mangled in some fashion would be exposed to microscopic asbestos fibers that would separate and take to the air in dust clouds or industrial waste. Those fibers were inhaled or in some cases ingested unknowingly, causing the development of mesothelioma or asbestosis decades later. Family members who were exposed to asbestos fibers that came home on work clothes and shoes also developed the disease.
Mesothelioma Latency Period
One of the traits that makes this disease unusual and to a degree insidious is the inordinately long period of latency associated with it. Mesothelioma has a twenty to fifty year latency period, meaning that people who develop the disease generally do so between two and five decades after their exposure to asbestos fibers occurred. That leads to a couple of medical complications. Most people who are victims of mesothelioma develop it well past the age of fifty, when some of the common ailments associated with our later years also begin to develop.
Moreover, many of the mesothelioma symptoms are similar to symptoms associated with more common diseases, which combined with the long latency period makes diagnosis difficult. The fact that mesothelioma is a relatively rare disease also means that other, more common diseases with similar symptoms must be ruled out first. The result can be a long period before an accurate diagnosis is made, on a form of cancer that grows rapidly.
Pleural Mesothelioma Symptoms
When mesothelioma develops on the pleura, it usually causes pleural thickening and in many instances causes the pleura to become fibrous and harden. That constricts the lung movement somewhat and makes breathing more difficult. Another common occurrence is the development of pleural effusion, which is the accumulation of excess fluid in the area of the lungs. This creates added pressure on the lungs as well as the chest cavity. Some of the symptoms are similar to the problems brought on by pneumonia, chronic bronchitis, cardiovascular disease or by other respiratory problems. The physical symptoms that impact the patient may include:
- A dry, consistent cough
- Shortness of breath
- Difficulty swallowing
- Weight loss
- Swelling in the upper body, especially the face and arms
- Lower back pain
- Pain in the side of the chest
- Muscle weakness
Peritoneal Mesothelioma Symptoms
When mesothelioma develops in the abdominal cavity it also commonly leads to the accumulation of excess fluid. The peritoneum becomes inflamed and begins to thicken as well and the impact on the abdomen is similar to what occurs in the chest cavity. The swelling and pressure impacts a different set of organs, however and creates a different group of physical symptoms that sends the patient to the doctor. Abdominal swelling is the first major observable sign, accompanied by abdominal pain. These symptoms are shared with a number of common ailments, which include appendicitis, gastrointestinal problems, liver disease, and pancreatitis. The generalized abdominal pain can be indicative of any number of afflictions. The physical symptoms that manifest may include:
- Stomach pain
- Weight loss
- Swollen belly
- Bowel obstruction
- Thrombosis in the legs
- Edema in the legs
Pericardial Mesothelioma Symptoms
The pericardium is the lining that surrounds the heart. When mesothelioma develops on this membrane, it often thickens and develops a rind-like quality, hardening and losing its flexibility. That puts pressure on the heart that can have a serious impact on cardiovascular functionality. The symptoms generated by this condition are similar to those associated with arterial coronary disease, coronary embolisms and congestive heart failure. Fluid accumulation or effusion in the pericardial area is also not unusual, putting further pressure on the heart. The result is a heart that shows signs of stress and chest pains that are usually associated with heart problems. Physical symptoms include:
- Heart palpitations
- Chest pain
- Shortness of breath
- Persistent coughing
- Fever or night sweats
Diagnosing Mesothelioma Symptoms
Malignant mesothelioma is typically a diffuse cancer, meaning that many small tumors form over the surface of the mesothelium membrane. In most, but not all, cases this means there is no large tumor that can be readily identified with medical imaging equipment. What X-rays and CT scans do pick up is the existence of excess fluid accumulation, which can lead to further tests to determine the cause of the effusion. One of those tests is extracting a fluid sample to be tested for mesothelioma markers – which might be certain proteins or actual malignant cells. Fluid extraction for pleural effusion is generally done with thoracentesis, a procedure that involves inserting a needle into the chest cavity. A similar process is used for peritoneal effusion, often accompanied by a laparoscopy to allow for a visual inspection of the abdominal area.
Medical imaging can also sometimes highlight a thickened mesothelium, particularly in the pleural area. Determining whether or not there are malignant cells present usually requires a biopsy however. That is usually done with a minor surgical procedure, extracting tissue to determine with certainty whether malignant mesothelioma is present.
- Risk Factors for Mesothelioma, National Cancer Institute, http://www.cancer.gov/cancertopics/factsheet/Sites-Types/mesothelioma
- Mesothelioma Overview, Mayo Clinic, http://www.mayoclinic.org/mesothelioma/
- How is Malignant Mesothelioma Diagnosed? American Cancer Society, http://www.cancer.org/docroot/CRI/content/CRI_2_4_3X_How_is_malignant_mesothelioma_diagnosed_29.asp?sitearea=
- Mesothelioma Diagnosis National Cancer Institute, http://www.cancer.gov/cancertopics/factsheet/Sites-Types/mesothelioma