The early
detection of mesothelioma is critical to the patient outlook and in
determining applicable treatment options.
However, mesothelioma is often difficult to
diagnose for a variety of reasons. Because mesothelioma is a rare
disease, many doctors are not familiar with it. In addition,
the non-specific nature of
patient symptoms can be indicators of other medical conditions. The
extended length of time between asbestos exposure and a patient's
symptomatic responses, often between 15-50 years, further hinders
immediate detection of mesothelioma. Despite these difficulties there
are many procedures available for the accurate diagnosis of mesothelioma.
Initial Evaluation
The initial patient evaluation(s) are critical in identifying
patients at risk for developing mesothelioma.
To establish risk factors and the presence
of symptoms, your physician will complete a medical history that
includes questions to help determine the timeframe and environment in
which you may have been exposed to asbestos. Communication between the
patient and doctor is important so that the earliest possible detection
of mesothelioma can be made. Make certain that you have shared all
relevant information regarding previous work history and possible
asbestos exposure with your physician.
In addition to constructing a medical profile and detailed medical
history, a complete physical examination will be performed. During a
physical exam your doctor may look for the following:
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Breath Sounds: listening to
the chest cavity as the patient inhales/exhales there may be an
absence of breath sounds, or these sounds may be muted. The absence
of, or muted nature of, these breath sounds may be an indication of
fluid in the chest cavity, or of pleural effusions.
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A doctor may listen to the
chest cavity while having the patient make vowel sounds - comparing
the sound resonance in the right and left chest cavities. Muted, or
dull, sounds between the cavities could be an indicator of a buildup
of fluid.
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By percussing, or tapping, on
the chest area a doctor may notice a dull, solid thumping sound,
rather than a hollow resonance. This may also indicate the presence of
fluid, or a mass, in the chest cavity.
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A physical examination will
also check for enlarged lymph nodes.
There are often very few signs
during an initial physical exam that would identify the presence of
mesothelioma. On the basis of patient symptoms, medical history, the
presence of specific risk factors (work environment, asbestos exposure),
and a complete physical examination, the doctor can use one or more of
the methods described below to determine if the disease is present.
Diagnostic Tests
Doctors use a variety of diagnostic procedures to determine if a patient
has mesothelioma. Comparing results from imaging scans, tissue biopsies,
pulmonary function tests, and other diagnostic techniques, the presence
of mesothelioma can be identified.
- Imaging Techniques
There
are many available technologies that allow doctors to view, or image,
organs and tissue that might show the presence of fluid or tumors.
A chest x–ray may show an unusual thickening of the
pleura, lowering of the lung fissures (spaces between the lobes of
the lungs), an accumulation of fluid in the lungs (pleural effusion),
and/or an irregular mass in the chest cavity.
A
CT (computed tomography) scan uses x-ray and computers to give
more sophisticated and detailed pictures of the insides of our body
than conventional x-rays. A rotating x-ray beam is used to take a
series of pictures of the body from different angles. A computer
combines the series of pictures to produce a detailed cross-sectional
image of a specific part of the body. The CT scan allows a radiologist
to see distinct aspects of the lungs and pleura.
Magnetic
Resonance Imaging (MRI) uses a strong magnetic field and
radiowaves to scan the body. There is no radiation involved. This
imaging method produces a series of cross-sectional pictures. MRI
scans are useful for viewing 'soft tissues' in the body and can show
the extent of mesothelioma. New MRI techniques where surface imaging
techniques are combined with quick breath-holding sequences and
gadolinium contrast medium give images, which detect tumor growth in
the pleura and thoracic wall better than the previous methods. MRI
images tend to be quite clear and are superior to routine x–ray
images.
Positron
Emission Tomography (PET) scans use a camera that produces
powerful images of the body’s biological functions. Because cancers
and other disease processes metabolize sugars at a higher rate than
normal tissues or organs, the PET scan uses tracers to indicate where
there is abnormal metabolic activity and can pinpoint the regions of
active disease. PET scans can also identify extremely small cancerous
cells, indicate benign or malignant cells, and help determine whether
treatment therapies are working.
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Pathological Tests
Mesothelioma is diagnosed by pathological examination. Tissue is
removed, put under the microscope, and a pathologist makes a
definitive diagnosis, and issues a pathology report.
A
tissue sample of a pleural or pericardial tumor can be obtained using
a relatively new technique called thoracoscopy. A thoracoscope
(telescope-like instrument connected to a video camera) is inserted
through a small incision into the chest. The doctor can see the tumor
through the thoracoscope and can use special forceps to take a tissue
biopsy.
A laparoscopy can be used to see and obtain a biopsy of a
peritoneal tumor. In this procedure, a flexible tube is attached to a
video camera that is inserted into the abdominal cavity via small
incisions. Fluid can also be collected during thoracoscopy or
laparoscopy.
A bronchoscopy may be performed if pleural mesothelioma is
suspected. In this process, the doctor inserts a flexible lighted tube
down the trachea, and into the bronchi to check for masses in the
airway. At that time, small samples of abnormal-appearing tissue may
also be removed for testing.
Lymph nodes are collections of immune system cells that help the body
fight infection. By examining the lymph nodes, the doctor can
determine if the cancer has spread. During a mediastinoscopy, a
patient has a lighted tube inserted under the sternum (chest bone) at
the neck level and then moved down into the chest. The surgeon can see
the lymph nodes and take tissue samples to check for cancer. This
procedure can also help the physician determine if you have lung
cancer or mesothelioma.
- Pulmonary Function Tests (PFT’s)
PFTs encompass a wide variety of tests that evaluate the entire
respiratory system. The tests are useful in the assessment and
diagnosis of pulmonary disease and aid in determining a course of
treatment. PFTs can be a simple peak flow measurement, or complex body
plethysmography and ventilation/perfusion scans which are performed in
hospitals and clinics. PFTs can also be useful in monitoring patient
response to treatment.
Although Mesothelioma can often be
difficult to initially detect, the above medical procedures and
diagnostic tests can lead to a clear diagnosis. Early medical diagnosis
is one of the primary variables affecting long-term prognosis.
Click here to learn more about available treatment options.
Staging is a method of evaluating the
progress of cancer in a patient. It looks at the mesothelioma and the
extent to which it has developed and its possible spread to other parts
of the body |