What is Mesothelioma?

What is Mesothelioma?

Mesothelioma cancer, or malignant melanoma, is a rare but deadly form of cancer that develops in the lining of the lungs, or, more rarely, the abdominal cavity, the heart, or the testes.

Types of Mesothelioma

There are four types of mesothelioma, and each has been associated with asbestos exposure:

  • – affects the pleura, or the lining that coats the lungs and chest wall. Pleural mesothelioma accounts for about 75 percent of all cases of mesothelioma.
  • Peritoneal mesothelioma – involves the peritoneum, which lines the inside of the abdomen and many of the abdominal organs. Peritoneal mesothelioma accounts for about 25 percent of all mesothelioma cases.
  • Pericardial mesothelioma – affects the lining around the heart. Pericardial mesothelioma is extremely rare.
  • Tunica vaginalis mesothelioma, or testicular mesothelioma – involves the sac surrounding the testicles, and is also extremely rare.

Asbestos exposure also increases the risk for the incurable, chronic lung disease asbestosis as well as cancers of the lung, larynx and kidney.

Risk Factors for Mesothelioma

Mesothelioma is caused by asbestos exposure. Asbestos is a fibrous, fire resistant mineral that has been widely used in many industrial products including cement, brake linings, roof shingles, flooring products, textiles, and insulation. It can also be found in talc, including talcum powders like those found in baby powder and some cosmetics.

The microscopic fibers of asbestos can remain airborne for days, and can be inhaled or swallowed by those in close proximity. When asbestos enters the body, the results can be deadly.

Millions of people have been exposed to asbestos, especially in the workplace. Those at greater risk of asbestos exposure include miners, factory workers, insulation manufacturers and installers, railroad and automotive workers, ship builders, gas mask makers, plumbers and construction workers.

Family members who work in environments where they are exposed to asbestos can also be at risk for secondary asbestos exposure, because the fibers can adhere to workers’ clothes and be carried home. For example, washing the clothes of someone who works around asbestos is at risk of asbestos exposure and thus mesothelioma.

Mesothelioma can remain latent in those exposed for 10 to 50 years. Once symptoms appear and a person is diagnosed with the disease, mesothelioma prognosis is dire. The disease usually proves fatal within 12 to 24 months.

Symptoms of Mesothelioma

Mesothelioma symptoms vary depending on where in the body the disease originates:

Pleural mesothelioma symptoms

  • Pain in the side of the chest or lower back
  • Shortness of breath
  • Cough
  • Fever
  • Excessive sweating
  • Fatigue
  • Unexplained weight loss
  • Difficulty swallowing
  • Hoarseness
  • Swelling of the face and arms

Peritoneal mesothelioma symptoms

  • Abdominal pain
  • Swelling or fluid in the abdomen
  • Unexplained weight loss
  • Nausea and vomiting
  • Constipation

Pericardial mesothelioma symptoms

  • Palpitations or irregular heartbeat
  • Chest pain
  • Heart murmurs
  • Cough
  • Difficulty breathing, even at rest
  • Orthopnea, or difficulty breathing when lying down
  • Fatigue
  • Fever or night sweats

Tunica vaginalis mesothelioma (testicular mesothelioma)

  • Hydrocele (buildup of fluid in the scrotum)
  • Abnormal lump inside the scrotum
  • Pain and swelling of the testes

Diagnosing Mesothelioma

Diagnosing mesothelioma can be difficult because the symptoms are similar to a number of other conditions. When patients visit a medical professional reporting signs or symptoms of mesothelioma, the doctor will want to get a medical history to learn about possible risk factors, such as asbestos exposure.

The doctor may perform a series of diagnostic tests – including imaging tests like X-rays, MRIs, CTs and PET scans; blood tests; and biopsies – to accurately diagnose mesothelioma. Which tests are performed often depends on the type of symptoms.

Diagnostic tests for mesothelioma include:

  • Chest X-ray – is typically ordered for patients with symptoms such as constant cough or shortness of breath, but it is not useful in detecting mesothelioma early. Findings that might suggest mesothelioma include abnormal thickening of the pleura, calcium deposits on the pleura, fluid between the lungs and chest wall, or changes in the lungs.
  • Ultrasound – also called sonography, uses high-frequency sound waves to produce pictures of the inside of the body. Ultrasounds are 90 percent accurate at detecting testicular tumors and are often used to when patients present with symptoms of tunica vaginalis mesothelioma, or testicular mesothelioma.
  • Echocardiogram – uses sound waves to capture images of the heart’s chambers, valves, walls and the blood vessels attached to the heart. An echocardiogram can show how well the heart is functioning.
  • Computed tomography (CT) scan – CT scans use X-rays to make detailed, cross-sectional images of the body. These X-rays are then combined into images of slices of the body. If mesothelioma is suspected, a CT scan will allow a doctor to determine the exact location of the cancer, whether it has spread to other organs, and whether treatments are effective.
  • Magnetic resonance imaging (MRI) scan – is similar to CT scan in that MRI scans make detailed images of the body’s soft tissues. But, MRIs use radio waves and strong magnets instead of X-rays. Prior to testing, patients are injected with a contrast material called gadolinium. This provides better contrast in the images captured. MRI scans can help show the exact location and extent of a tumor.
  • Positron emissions tomography (PET) scan – detects cancer cells in the body. During a PET scan, patients are injected with a radioactive substance, typically a type of sugar because cancer cells absorb more sugar than most other cells. The level of radioactivity is very low. During a PET scan, a camera creates a picture of the areas of radioactivity in the body. This test does not give as much detail as a CT or MRI scan, but can help determine whether cells seen in other imaging tests are likely cancerous or not, and to determine whether cancer has spread to other parts of the body. Some machines can do a PET and CT scan at the same time.
  • Blood tests – can pick up on markers, or higher levels of certain substances, in the blood that helps doctors narrow in on a diagnosis of mesothelioma. These substances include osteopontin and soluble mesothelin-related peptides (SMRPs).
  • Fluid and tissue sample tests – may strongly suggest a patient has mesothelioma, but the actual diagnosis is made by performing a biopsy. During a biopsy, cells are removed from an abnormal area and looked at through a microscope. Biopsies can be performed in different ways depending on a patient’s situation.
    Once mesothelioma is diagnosed, a doctor will determine the type of mesothelioma, the staging, and recommend a course of treatment.

Treatment of Mesothelioma

After mesothelioma has been diagnosed and staged, treatment options will be discussed with the patient. Options may include surgery, radiation therapy, and/or chemotherapy. Some patients may be candidates for clinical trials to test new therapies.

The risks and benefits of each treatment will be discussed with patients to determine the best course of action. For some, palliative procedures may be used to help ease symptoms of the disease.