How Lung Cancer Is Diagnosed
With Lung Cancer
A Guide for Patients and Their Families
cancer will usually be suspected in a smoker who has a change
in respiratory symptoms, unexplained weight loss or bone pain.
It is often discovered in the first few years after a person
has quit smoking, perhaps because of a cough or other subtle
change in symptoms.
lung cancers are picked up on a routine chest X-ray in a person
experiencing no symptoms. If cancer cells start to grow in
one of the bronchioles (the smallest branches of the breathing
tree) near the aveoli (tiny air sacs), the tumor can become
the size of a golf ball or even larger without causing symptoms.
Even when the chest X-ray looks normal, cancer may be suspected
if the person has coughed up blood, develops persistent hoarseness,
has chest pain or difficulty in breathing, or has had repeated
episodes of pneumonia in the same place in the lung.
Sometimes small ulcers appear on a lung tumor and make it
bleed. About half of lung cancer patients have blood or streaks
of blood in their sputum. You may see streaks of blood in
the mucus that you cough up. Heavy bleeding, however, is rare.
a tumor on the lining of a breathing tube grows, it may block
the free flow of air through the breathing tube, resulting
in a wheeze or a whistling noise. A deep breath may cause
chest pain or shoulder pain, shortness of breath, or noisy
breathing. If the tumor damages one of the nerves that goes
to the larynx (voice box), hoarseness may result.
pain and difficulty in breathing may also result if the tumor
spreads to the outside surface of the lung, causing fluid
to collect in the pleural cavity, the space between the lung
and ribs. If a tumor presses on the blood vessels that carry
blood to and from the heart, the normal blood flow may be
growing tumor may interfere with the normal movement of mucus
up and out of the lungs, causing a cough or making an existing
cough worse. When it blocks a main breathing tube, it can
cause shortness of breath. It may also keep the mucus produced
in the bronchial tubes from being swept upward (past the tumor)
and out of the lungs, as it should. So the mucus backs up
in the lung, causing a type of pneumonia.
the first sign of lung cancer is pneumonia, with fever, chills,
and chest pain. There may also be a cough with yellow sputum
when the tumor blocks off a bronchial tube and infection develops
behind the blockage. If a tumor spreads directly from the
lung into the tissues of the chest wall, it may cause pain.
It may grow from the lung toward the center of the chest,
between the lungs, and press on the esophagus (swallowing
tube). This pressure may make swallowing difficult until the
tumor is found and treated.
the first symptoms are in an area outside of the chest to
which the cancer has spread. There may be headache or dizziness,
bone pain, or lymph node enlargement. Persistent hoarseness
may develop, as well as clubbing, a rounding and widening
of the nails and fingertips.
and diagnostic tests
Both your general health and your respiratory status will
be evaluated. A detailed medical history will be taken. You
will be asked about previous illness, smoking and occupational
history, respiratory symptoms and general health. A complete
physical examination will be done with special attention to
the lungs, the lymph nodes in your neck and underarms, and
the abdomen. If surgery is a possibilty, your doctor needs
to determine whether you can tolerate surgery.
different kinds of tests may be used: several kinds of X-ray
examinations, as well as other methods of obtaining a picture
of the inside of the body. Your doctor will decide which ones
you need. Instruments may be used to look into various parts
of the body, and in some cases specimens will be taken for
examination in the laboratory. Sputum, blood, urine and other
body fluids will be examined. If necessary, an operation will
be performed to complete the diagnosis.
some people believe that lung cancer can be diagnosed by a
blood test, this is not true. Blood tests may help determine
whether the cancer has spread to an organ such as the liver,
but such tests must be done in conjunction with other studies.
may be given one or more of the following tests.
Since lung cancer can usually be seen on the X-ray film, a
chest X-ray is one of the first tests you will have. As with
most types of X-ray pictures, a chest X-ray causes no discomfort.
smallest tumor that can be seen on a chest X-ray is about
1/2-inch in diameter. But even if a tumor is not seen, the
chest X-ray may offer other clues to the diagnosis, such as
pneumonia in the lung. Other possible clues are enlarged lymph
nodes (which may be filled with cancer cells), and pleural
effusion, an accumulation of fluid in the space between the
lung and the chest wall. Lung cancer is not always the cause
of these, but they are signs that alert the doctor to look
for the cause, using other diagnostic tools.
doctor may want you to have a chest X-ray even if the diagnosis
is already clear. The purpose is to be able to compare it
with previous and later X-rays, to follow your progress and
watch for possible changes in the lung tissue. It is important
for your doctor to find out whether the cancer is growing,
or whether it is responding to treatment and shrinking.
scan (also called CT scan)
Patients with suspected lung cancer will almost always have
a CAT (computerized axial tomography) scan of the chest and
upper abdomen to help in diagnosis and staging. Other areas
such as the head or back may be scanned if worrisome symptoms
CAT scan is a type of X-ray study combined with computer processing
to provide a much more detailed picture of the lymph nodes
and blood vessels in your lungs and chest than an ordinary
chest X-ray can. Your doctor will be able to make a more exact
evaluation of the size and extent of the tumor, the presence
of enlarged lymph nodes, and whether bones or vital structures
and organs are involved.
allow a better picture, dye will probably be injected into
a vein in your arm. Be sure to inform your doctor if you have
ever had an allergy to X-ray dye or to seafood. Aside from
the needle stick for the dye, a CAT scan is painless. The
X-ray machine will move around you and you will be asked to
hold your breath for several seconds as pictures are taken.
(magnetic resonance imaging)
With this technique, detailed pictures of various organs are
obtained using a magnetic field. It is painless, but may involve
lying in a confined space for up to 30 minutes. If you think
that being in an enclosed space may make you uncomforable
or anxious, ask about receiving a mild tranquilizer before
the test. (Some newer MRI machines are more open.) The MRI
is usually used for brain imaging when headache is one of
the symptoms. It may also be used to evaluate blood vessel
or bone involvement of a lung tumor, when this information
is not clear on the CAT scan.
You may be asked for a sputum sample, so it can be examined
under the microscope for the presence of cancer cells. In
this way, the diagnosis of lung cancer and its specific cell
type can sometimes be made without the need for more invasive
testing. If you are unable to cough up a deep sputum sample,
you may be given a mist of moisturized air to inhale, to stimulate
A flexible lighted tube called a fiberoptic bronchoscope is
used to examine the airways, to see the tumor. The doctor
needs to learn its type and exact location. This information
is important for deciding whether surgery will be possible.
If the tumor is not visible, an X-ray can help localize it
so that the doctor can obtain biopsies through the bronchoscope.
is usually an outpatient procedure. You will be asked to arrive
with an empty stomach and to bring a friend or relative who
will be able to drive you home.
the procedure, you will lie on a padded table equipped with
an X-ray machine. A technician will connect you to heart,
blood pressure and oxygen monitors. You will be given a local
anesthetic as a mist, either to inhale or as a throat spray,
and then sedated through a small IV in your hand or arm. Your
nose will be numbed with an anesthetic gel, and then the scope
will enter your nose and travel through the nose into your
airway. Fluid is washed into your lung through the scope to
allow cells to be collected for examination. Biopsies will
most likely also be done.
are no pain fibers in your lung, so the biopsies will not
hurt. You will be closely monitored during the procedure and
may spend a couple of hours in a recovery room. The main discomfort
of bronchoscopy is from coughing, and your throat may be a
little sore. If biopsies are done, you may cough up a small
amount of blood.
biopsy (fine needle aspiration biopsy)
Sometimes a tumor is located in a place that is easier to
biopsy from the outside than through the bronchoscope. In
that case a radiologist will perform the biopsy, using an
X-ray or CAT scan to locate the tumor.
skin will be numbed with a local anesthetic, then a needle
will be inserted through the skin between the ribs and into
an area of disease in the lung. X-ray guidance ensures that
the needle is inside the pulmonary lesion. Cells removed from
the tumor will be examined under the microscope for evidence
is a small chance that air will escape from your lung causing
some degree of lung collapse (pneumothorax). You will have
a chest X-ray after the procedure and will be observed for
an hour or two to assure that all is well. This is usually
a minor problem and the lung re-expands without any special
treatment. If the collapse is more complete, air will need
to be removed from the pleural space by inserting a tube between
the ribs and into the chest, and connecting the tube to a
biopsy report. All biopsies, whether taken through the
bronchoscope or a needle, need to be processed and then read
by a pathologist. This process may take 1 to 3 days. The wait
will be difficult for you, but it is important. There is a
possibility that your biopsy will come back "negative"
(no cancer), even if there is cancer. The tumor may be in
an area that is difficult to reach, for example. Your physician
may recommend surgery to remove a suspicious nodule, even
when the biopsy does not show cancer.
If surgery is a possible treatment, you must have enough lung
capacity to allow part of your lung to be removed. Measuring
lung capacity is especially important if you are (or were)
a cigarette smoker because smoking is also a risk factor for
emphysema, and if you have emphysema, your lung capacity might
capacity is determined by measuring the amount of gas you
can blow out of your lung with maximum effort. This will be
hard work, but do your best. You will likely have blood drawn
from an artery in your wrist to measure oxygen and carbon
dioxide levels in your blood, which also helps determine how
well your lungs are working.
If your lung function is decreased, you may be asked to have
a nuclear medicine lung scan to evaluate lung function in
more detail. In this test, a tiny amount of radioactive material
is placed in your vein and a machine scans over your lungs.
The information gained helps the physician determine whether
your right and left lungs share equally in your lung capacity
and whether you will have sufficient lung capacity after part
or all of one lung is removed. In some instances, exercise
testing on a bicycle or treadmill may also be used to evaluate
your lung capacity and your ability to tolerate surgery.
The chest X-ray may show fluid in the space between the lung
and the chest wall -- a pleural effusion. There are many possible
causes of such fluid; one cause is spread of cancer to the
pleural space. If cancer cells are found, surgical cure is
not possible. Therefore the fluid must be examined. This is
done by means of a minor procedure called thoracentesis.
the procedure, your chest wall (usually in the back) is cleaned
and numbed with a local anesthetic. Then a needle is introduced
between the ribs into the pleural space and fluid is gently
withdrawn. Sometimes a slightly larger needle is used for
a biopsy. The fluid and/or biopsy are examined for cancer
cells. Thoracentesis can also provide relief of symptoms if
you have a large amount of fluid that is causing shortness
of breath or chest pain.
These are surgical procedures that are performed under general
anesthesia in the operating room.
-- named for the instrument used -- is usually used if you
have a nodule (rounded abnormality) at the edge of the lung,
and it has not been diagnosed as cancer by a previous biopsy.
The surgeon makes three small chest incisions for inserting
a scope and biopsy instruments. The nodule is removed and
examined by the pathologist under the microscope. If cancer
is found, the surgeon will remove the lobe with the nodule
(thoracotomy), usually at the same time. For thoracoscopy
alone, the hospital stay is about 2-3 days.
-- frequently an outpatient procedure -- is named for
the mediastinum, the area of the chest behind the breastbone.
It is used in evaluating the lymph nodes in the center of
the chest, to determine whether cancer has spread. The surgeon
inserts a scope through a small curved incision at the base
of the neck, at the top of the breastbone. Biopsies are taken
through the scope. This procedure can establish a definite
diagnosis when the X-ray or CAT scan has shown enlarged lymph
nodes. It may also be done as a staging procedure when a curative
operation is planned, to assure that the cancer has not spread
to the central lymph nodes. (If cancer is found in these nodes,
an operation to remove the lung tumor will usually be delayed
until it is determined whether pre-operative treatment with
chemotherapy and/or radiation therapy would be helpful.)
may be done when the chest X-ray is suspicious for cancer,
but cancer has not been definitely diagnosed. It is a way
to biopsy the suspicious area. The surgeon makes an incision,
several inches long, in your chest to allow removal of a tumor
and the surrounding lung tissue. The tissue is examined by
a pathologist. If cancer is diagnosed and is a type that can
be effectively treated by surgery, the surgeon will perform
the operation at that time. The diagnosis and treatment will
be accomplished with the same operation.
Most of the remaining diagnostic procedures are for finding
out whether the cancer has spread to any other organs. For
example, if you have pain that feels as if it comes from bone,
you may have a bone scan. Much like an X-ray, a bone scan
is painless. A small amount of sterile, radioactive liquid
is injected into a vein in your arm. The amount of radioactivity
is small and is harmless to you. If there are any cancerous
spots in the bone, they will absorb the radioactive liquid
and show on the scan, indicating that the disease has probably
spread to that bone. The doctor will then check for metastatic
cancer with X-rays of those bones.
liver is another place where lung cancer cells can start growing.
A liver scan may be ordered if your liver feels abnormally
large during the examination, or if certain blood tests indicate
that it is not working properly.