Malignant Mesothelioma

Malignant mesothelioma is a form of asbestos cancer that affects the thin tissue layer surrounding the body's internal organs, called the mesothelium. The cancer is almost exclusively caused by asbestos exposure.

Malignant Mesothelioma Types

How Many and What Type of Malignant Mesothelioma Deaths Occurred in 1999.

Medical professionals divide malignant mesothelioma into various types depending on which area of the mesothelium is affected:

• Pleural mesothelioma is the most common form of the cancer, affecting the lining of the lungs, called the pleura.
• Peritoneal mesothelioma is the second most common form of the cancer and develops in the lining of the abdomen, called the peritoneum.
• Pericardial mesothelioma develops in the membrane that surrounds the heart, called the pericardium.
• Testicular mesothelioma is the rarest form of the cancer and develops in the membranous lining surrounding the testicles, called the tunica vaginalis.

Malignant Mesothelioma Symptoms

Patients with malignant mesothelioma generally do not display any symptoms until 20 to 50 years after exposure to asbestos occurs. This is due to the long latency period (the amount of time it takes for a patient to demonstrate symptoms after initial exposure to a disease-causing agent) associated with mesothelioma. The symptoms of mesothelioma are very general and often resemble less serious conditions, which can make diagnosis difficult.
Symptoms vary depending on the type of mesothelioma a patient has, but the most common symptoms expressed by pleural mesothelioma patients include shortness of breath, chest pain and persistent cough. Peritoneal mesothelioma patients may display symptoms such as abdominal swelling, changes in bowel movement and development of lumps under the skin on the abdomen. Patients with pericardial mesothelioma may experience heart palpitations, chest pain, difficulty breathing and fever or night sweats. Testicular mesothelioma patients may notice testicular lumps.

Malignant Mesothelioma Treatment

Regardless of the type of malignant mesothelioma a patient has, treatment options are available for all mesothelioma patients, though a patient’s response to different treatments will vary. The stage , or level of maturity of the cancer, as well as the patient’s general health are greatly considered when a doctor creates a treatment plan.
Common curative treatments, or treatments designed to remove cancer cells and cure the disease, for mesothelioma patients include surgery, chemotherapy and radiation. Chemotherapy and radiation treatments aim to kill cancerous cells and stop rapid cell division and growth. Though harmful cells are targeted, the treatments can also affect healthy cells. Patients may experience side effects such as nausea throughout treatment.
Palliative treatments, designed to increase a patient’s comfort and ease pain, may also be recommended. Patients may also wish to explore experimental treatments offered in the studies testing up-and-coming drugs or procedures called clinical trials.

Malignant Mesothelioma Causes

The only proven cause of malignant mesothelioma is asbestos exposure . Mesothelioma develops when asbestos fibers are inhaled or ingested and become lodged in the organs of the body. Overtime the fibers cause scarring and inflammation, which can eventually lead to the development of mesothelioma. The asbestos fibers cause cellular damage; resulting in the rapid division of cancers cells. The rapidly producing cells cause the affected membrane to thicken, resulting in fluid buildup in the spaces between the membrane layers. As the cells continue to divide and grow, tumors form. Unfortunately it typically takes between 20 and 50 years for a patient to demonstrate symptoms of mesothelioma, which frequently allows the cancer to progress to mature stages, making treatment more difficult.

Malignant Mesothelioma Types

In biological terms, malignant mesothelioma is divided into three types: epithelial, sarcomatoid and biphasic. These classifications pertain to the shape and structure of the cancer cells.

Diagram of Malignant Mesothelioma Types.

Between 50 to 70 percent of malignant mesothelioma cases are epithelial, approximately 20 to 35 percent are biphasic, and 7 to 20 percent are sarcomatoid. Epithelial cells are marked by their well-defined and uniform shape and can closely resemble cells of another form of cancer known as adenocarcinoma. Sarcomatoid cells display an elongated spindle shape, which tend to be irregular rather than uniform in shape, and the cells often overlap one another. Cells of the biphasic variety contain both epithelial and sarcomatoid cells, which form in groups of like cells rather than displaying a uniform mixture.
Diagnosing what type of malignant mesothelioma a patient has can be challenging. One contributing factor is that it can be difficult to differentiate mesothelioma from adenocarcinoma, a cancer originating in glandular tissue, on small tissue specimens.

Mesothelioma ICD-9 Code

Pleural mesothelioma may also be referred to as ICD-9 code 163, a disease category and mesothelioma diagnosis code that represents malignant neoplasm of the pleura. Peritoneal mesothelioma may be called ICD-9 code 158, which accounts for malignant neoplasm of the retroperitoneum and peritoneum. Pericardial mesothelioma falls under the category ICD-9 code 164, which represents malignant neoplasm of the thymus, heart and mediastinum