Mesothelioma is a rare form of cancer where malignant
cells are found in the mesothelium, a protective sac
that covers most of the body’s internal organs.
Whilst mesothelioma is certainly not a common aging
condition, it is included here as its symptoms are difficult
to diagnose, as many are similar to symptoms of common
Most people who develop mesothelioma have worked on
jobs where they inhaled asbestos particles, although
mesothelioma can also occur due to contact with older
types of x-rays and some minerals found in the ground,
similar to asbestos.
The mesothelium membrane is composed of two layers
- a layer immediately surrounding the organ
- a layer forming a sac around the organ
The mesothelium produces a lubricating fluid that
is released between these layers, allowing moving organs
such as the heart and the lungs to glide easily against
Typcial mesotheliums include:
Peritoneum - covers most of the organs
in the abdominal cavity. Peritoneal mesothelioma account
for 10% to 20%
Pleura - surrounds the lungs and
lines the wall of the chest cavity. Pleural mesothelioma.
Accounts for 75% of cases
Pericardium - covers and protects
the heart. Pericardial mesothelioma is very rare
Tunica vaginalis testis - surrounding
the male internal reproductive organs. Very rare
Tunica serosa uteri - covers the
internal reproductive organs in women. Very rare
Tumors of the mesothelium can be benign [noncancerous]
or malignant [cancerous]). A malignant tumor of the
mesothelium is called a malignant mesothelioma. Because
most mesothelial tumors are cancerous, malignant mesothelioma
is often simply called mesothelioma.
Mesothelioma is cancer of the mesothelium, invading
and damaging nearby tissues and organs. These cancer
cells can also metastasise, spreading from their original
site to other parts of the body. Most cases of mesothelioma
begin in the pleura or peritoneum.
Malignant mesothelioma is an uncommon, but no longer
rare. It is difficult to diagnose and poorly responsive
There are three main types of malignant mesothelioma:
- epithelioid - 50% to 70% of mesothelioma occurrences.
This type has the best prognosis.
- sarcomatoid type (7%-20%), and
- the mixed/biphasic type (20%-35%).
Treatment options for all three types are the same.
Previous exposure to asbestos fibers even single exposures
to very low doses of fibers can produce serious long-term
Almost anyone who has inhaled asbestos dust is at risk.
This includes a worker's family and friends due to asbestos
carried on clothing.
Exposure to asbestos dust can occur at major construction
job sites, in shipyards, in industry, and during construction
or renovation of commercial buildings.
A history of asbestos exposure at work is reported
in about 70 percent to 80 percent of all cases. However,
mesothelioma has been reported in some individuals without
any known exposure to asbestos.
Since the early 1940s, millions of American workers
have been exposed to asbestos dust. This includes: shipyard
workers, people who work in asbestos mines and mills,
producers of asbestos products, workers in the heating
and construction industries, and other tradespeople.
The risk of asbestos-related disease increases with
heavier exposure to asbestos and longer exposure time.
Not all workers who are heavily exposed develop asbestos-related
Symptoms of Mesothelioma