What is Mesothelioma?

Malignant mesothelioma is a rare form of cancer that develops in the mesothelium which is a protective lining that covers most of the body’s internal organs. Mesothelioma is divided into three primary histological types: Epithelioid, Sarcomatoid and Mixed/biphasic.

Mesothelioma develops in three major areas of the body:

Pleura – the lining of the lung, resulting in pleural mesothelioma
Peritoneum – the abdominal cavity, resulting in peritoneal mesothelioma
Pericardium – the heart, resulting in pericardial mesothelioma

Most people with malignant mesothelioma have worked on jobs where they breathed asbestos.

A doctor should be seen if a person has shortness of breath, pain in the chest, or pain or swelling in the abdomen. If there are symptoms, the doctor may order an x-ray of the chest or abdomen.

The doctor may also look inside the chest cavity for mesothelioma with a special instrument called a thoracoscope. A cut will be made through the chest wall and the thoracoscope will be put into the chest between two ribs. This test, called thoracoscopy, is usually done in a hospital. Before the test, the patient is given a local anesthetic (a drug that causes a loss of feeling for a short period of time). Some pressure may be felt, but usually there is no pain.

The doctor may also look inside the abdomen (peritoneoscopy) for mesothelioma with a special tool called a peritoneoscope. The peritoneoscope is put into an opening made in the abdomen. This test is also usually done in a hospital. Before the test is done, a local anesthetic is administered.

If abnormal tissue is found, the doctor will need to cut out a small piece and have it looked at under a microscope to see if there are any mesothelioma cells. This is called a biopsy. Biopsies are usually done during the thoracoscopy or peritoneoscopy.

The chance of recovery (prognosis) from mesothelioma depends on the size of the malignant mesothelioma, where the mesothelioma is, how far the mesothelioma has spread, how the mesothelioma cells look under the microscope, how the mesothelioma responds to treatment, and the patient’s age.

Types of Mesothelioma

Mesothelioma is divided into three primary histological types:

Epithelioid mesothelioma - Epithelioid mesothelioma constitutes approximately 50% to 70% of all malignant mesothelioma making it the most common type of mesothelioma.
Sarcomatoid mesothelioma - Sarcomatoid mesothelioma is the least common type of mesothelioma accounting for about 10% to 15% of malignant mesothelioma.
Mixed or Biphasic mesothelioma - As its name implies, Mixed or Biphasic mesothelioma is combination of the sarcomatoid and epithelioid types. Approximately 20% to 40% of the mesothelioma cancer cases fall into the biphasic category.

Mesothelioma develops in three major areas of the body:

Pleura – the lining of the lung, resulting in pleural mesothelioma
Peritoneum – the abdominal cavity, resulting in peritoneal mesothelioma
Pericardium – the heart, resulting in pericardial mesothelioma

As malignant mesothelioma can be confused with other cancers, consider getting a second diagnostic evaluation from your physician or from a mesothelioma oncology specialist.

Symptoms of Pleural and Peritoneal Mesothelioma

Symptoms of mesothelioma may not appear until 30 to 50 years after exposure to asbestos. Shortness of breath and pain in the chest due to an accumulation of fluid in the pleura are often symptoms of pleural mesothelioma.

Symptoms of peritoneal mesothelioma include weight loss and abdominal pain and swelling due to a buildup of fluid in the abdomen. 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.

These symptoms may be caused by mesothelioma or by other less serious conditions. It is important to see a doctor about any of these symptoms. Only a doctor can make a mesothelioma diagnosis.