Mesothelioma Diagnosis
Mesothelioma
(cancer of the mesothelium) is a disease in which cells
of the mesothelium become abnormal and divide without control
or order. They can invade and damage nearby tissues and
organs. Cancer cells can also metastasize (spread) from
their original site to other parts of the body. Most cases
of mesothelioma begin in the pleura or peritoneum.
Although reported incidence rates have increased in the
past 20 years, mesothelioma is still a relatively rare cancer.
About 2,000 new cases of mesothelioma are diagnosed in the
United States each year. Mesothelioma occurs more often
in men than in women and risk increases with age, but this
disease can appear in either men or women at any age.
Recurrent
malignant mesothelioma is cancer that has recurred (come
back) after it has been treated. The cancer may come back
in the chest or abdomen or in other parts of the body.
Diagnosing
mesothelioma is often difficult, because the symptoms are
similar to those of a number of other conditions. Diagnosis
begins with a review of the patient's medical history, including
any history of asbestos exposure. A complete physical examination
may be performed, including x-rays of the chest or abdomen
and lung function tests. A CT (or CAT) scan or an MRI may
also be useful. A CT scan is a series of detailed pictures
of areas inside the body created by a computer linked to
an x-ray machine. In an MRI, a powerful magnet linked to
a computer is used to make detailed pictures of areas inside
the body. These pictures are viewed on a monitor and can
also be printed.
A biopsy
is needed to confirm a diagnosis of mesothelioma. In a biopsy,
a surgeon or a medical oncologist (a doctor who specializes
in diagnosing and treating cancer) removes a sample of tissue
for examination under a microscope by a pathologist. A biopsy
may be done in different ways, depending on where the abnormal
area is located. If the cancer is in the chest, the doctor
may perform a thoracoscopy. In this procedure, the doctor
makes a small cut through the chest wall and puts a thin,
lighted tube called a thoracoscope into the chest between
two ribs. Thoracoscopy allows the doctor to look inside
the chest and obtain tissue samples. If the cancer is in
the abdomen, the doctor may perform a peritoneoscopy. To
obtain tissue for examination, the doctor makes a small
opening in the abdomen and inserts a special instrument
called a peritoneoscope into the abdominal cavity. If these
procedures do not yield enough tissue, more extensive diagnostic
surgery may be necessary.
If the
diagnosis is mesothelioma, the doctor will want to learn
the stage (or extent) of the disease. Staging involves more
tests in a careful attempt to find out whether the cancer
has spread and, if so, to which parts of the body. Knowing
the stage of the disease helps the doctor plan treatment.
Mesothelioma
is described as localized if the cancer is found only on
the membrane surface where it originated. It is classified
as advanced if it has spread beyond the original membrane
surface to other parts of the body, such as the lymph nodes,
lungs, chest wall, or abdominal organs.
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 diagnosis.
