Mesothelioma, an agressive form of lung cancer resulting from exposure
to asbestos consists of two general types, pleural and peritoneal
mesothelioma. Below you will find a description of each individual
type of mesothelioma and their symptoms.
The term Mesothelioma is used to describe a
cancerous tumor that involves the mosothelial cells of an organ,
usually the lungs, heart or abdominal organs. The most common type is
pleural mesothelioma, a very agresive form of lung cancer. The
pleura is a thin membrane found between the lungs and the chest
cavity, which serves as a lubricant to prevent the lungs from chafing
against the chest walls. When pleural mesothelioma cancer spreads, the
cells of the mesothelium become abnormal. These malignant cells begin
to divide and spread without order and can begin to affect organs and
tissues in the immediate area. This often leads to complications in
the surrounding organs.
There are two types of Pleural Mesothelioma,
diffuse and malignant (cancerous), and localized and benign (non-cancerous).
Benign mesotheliomas can often be removed surgically, are generally
not life-threatening, and are not usually related to asbestos exposure.
Malignant mesotheliomas, even though rare, are very serious and
require more aggresive treatments.
The most serious type of mesothelioma, diffuse
malignant mesothelioma, is a cancer of the cells that make up the
pleura or lining around the outside of the lungs and inside of the
ribs and accounts for about 75% of all cases. Fluid build-up from the
pleural effusion can generally be seen on a chest x-ray and heard
during a physical examination, but a firm diagnosis of mesothelioma
can only be made through a biopsy and pathological testing. This is
important because there are also benign pleural effusions and other
tumors that have a similar appearance to mesothelioma. Diagnosing
mesothelioma can be quite difficult; it requires special lab stains,
and often considerable experience by the pathologist interpreting the
The spread of the tumor over the pleura causes
pleural thickening. This can reduce the flexibility of the pleura and
encase the lungs in an increasingly restrictive girdle. With the lungs
restricted, they get smaller and less functional, and breathing
becomes more difficult. At first a person with mesothelioma may be
breathless only when he or she exercises, but as lung function drops,
he or she can become short of breath even while resting.
The tumor spreads by direct invasion of surrounding
tissue. As it spreads inward it can compress the lungs. As the tumor
spreads outward it can invade the chest wall and ribs, and this can be
Current medical science does not know exactly how
and why, at a cellular level, asbestos fibers cause mesothelial cells
to become abnormal (malignant or cancerous.) Thus it is not known
whether only one fiber causes the tumor or whether it takes many
fibers. It seems that asbestos fibers in the pleura can start a tumor
as well as promote its growth; the tumor does not depend on any other
processes for its development.
Unfortunately there is as yet no known absolute
cure for malignant mesothelioma. The prognosis depends on various
factors, including the size and stage of the tumor, the extent of the
tumor, the cell type, and whether or not the tumor responds to
treatment. The treatment options for people with mesothelioma have
improved significantly, especially for those whose cancer is diagnosed
early and treated vigorously.
Some of the treatments currently available for
pleural mesothelioma include:
Intra-operative photodynamic therapy
Peritoneal mesothelioma is a tumor of the
peritoneum membrane. This thin membrane of mesothelial cells surrounds
and protects many of the organs in the abdomen. Asbestos exposure is
the only known cause of peritoneal mesothelioma in the U.S. However,
it can take decades before initial symptoms of this disease appear.
Peritoneal Mesothelioma accounts for about one-fifth of all
mesotheliomas diagnosed in the US each year.
While peritoneal mesotheliomas are less common than
pleural mesotheliomas, they tend to be more invasive, and thus often
result in a shorter life expectancy for the patient. Mesotheliomas
have also been found in the stomach and other abdominal organs.
Like all cancers, peritoneal mesothelioma can be
either benign or malignant. Even though symptoms of peritoneal
mesothelioma take years to develop, it is sometimes diagnosed by mere
coincidence and before any symptoms actually appeared.
Typical symptoms of peritoneal mesothelioma include
abdominal pains, weakness, weight loss, loss of appetite, nausea, and
abdominal swelling. Sometimes fluid accumulates in the peritoneal
space, which results in a condition known as Ascites. Most often than
none, the symptoms of peritoneal mesothelioma start of gradually, but
over time the symptoms can become more and more severe.
Although the first step towards detecting
peritoneal mesothelioma involve X-rays and CT scans, a definitive
diagnosis is only achieved through a biopsy, which usually involves
removing a tiny piece of tissue. However, this is generally only done
if the doctor finds an abnormality when viewing the peritoneum using a
precedure called peritoneoscopy. The tissue sample is then examined by
a pathologist who makes a diagnosis using microscopic analysis of
At this time, even though there are various
treatment options available, there is no known cure for peritoneal
mesothelioma. The prognosis depends on various factors, including the
size and stage of the tumor, its extent, the cell type, and whether or
not the tumor responds to treatment. However, an early diagnosis is
important and because of it relief and treatment of people with
peritoneal mesothelioma have improved dramatically.
Some of the treatments currently available for
peritoneal mesothelioma include: