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A patient's symptoms, physical exam, imaging tests, and
bloodtests may suggest that bone cancer is present. However, in most
cases,
doctors must confirm this suspicion by examining a tissue or cell
sample under a microscope (known as a biopsy). Other diseases, such as
bone infections, can cause symptoms and imaging results that could be
confused with bone cancer. Since a single bone metastasis can have the
same sign and symptoms as a primary bone tumor, many doctors require a
biopsy to diagnose a patient's first bone metastasis. After that,
additional bone metastases can usually be diagnosed based on x-rays and
other imaging tests.
Signs and symptoms of bone cancer
Pain
Pain in the affected bone is the most common complaint of
patients with bone cancer. At first, the pain is not constant. It may
be worse at night or when the bone is used (for example, leg pain when
walking). As the cancer grows, the pain will be there all the time. The
pain increases with activity and may result in a limp if a leg is
involved.
Swelling
Swelling in the area of the pain may not occur until weeks
later. It may be possible to feel a lump or mass depending on the
location of the tumor.
Fractures
Although bone cancer may weaken the bone it develops in, most
of the time the bones do not fracture (break). People with a fracture
next to or through a bone cancer usually describe sudden severe pain in
a limb that had been sore for a few months.
Other symptoms
Cancer can cause problems like weight loss and fatigue. If the
cancer spreads to internal organs it may cause symptoms too. For
example, if the cancer spreads to the lung, you may have trouble
breathing.
Bone pain and/or swelling are more often due to conditions
other than cancer, such as injuries or arthritis. Still, if these
problems go on for a long time without a known reason, you should see
your doctor.
Imaging tests to detect bone cancer
X-rays
Most bone cancers show up on x-rays of the bone. The bone at
the site of the cancer may appear "ragged" instead of solid. The cancer
can also appear as a hole in the bone. Sometimes doctors can see a
tumor around the defect in the bone that may extend into nearby tissues
(such as muscle or fat). The radiologist (doctor who specializes in
reading x-rays) can often tell if a tumor is malignant by its x-ray
appearance, although only a biopsy can absolutely determine that.
A chest x-ray is often done to determine whether bone cancer
has spread to the lungs.
Computed tomography (CT)
The CT scan is an x-ray procedure that produces detailed,
cross-sectional images of your body. Instead of taking one picture,
like a conventional x-ray, a CT scanner takes many pictures as it
rotates around you. A computer then combines these pictures into an
image of a slice of your body. The machine creates multiple images of
the part of your body that is being studied.
CT scans are helpful in staging cancer. They help tell if your
bone cancer has spread into your lungs, liver, or other organs. These
scans also show the lymph nodes and distant organs where metastatic
cancer might be present.
Before the first set of pictures is taken you may be asked to
drink 1 or 2 pints of a contrast agent. This helps outline the
intestine so that certain areas are not mistaken for tumors. You may
also receive an IV (intravenous) line through which a different kind of
contrast dye is injected. This helps better outline structures in your
body.
The injection can cause some flushing (redness and warm
feeling that may last hours to days). A few people are allergic to the
dye and get hives. Rarely, more serious reactions like trouble
breathing and low blood pressure can occur. Medication can be given to
prevent and treat allergic reactions. Be sure to tell the doctor if you
have ever had a reaction to any contrast material used for x-rays or if
you have an allergy to shellfish.
CT scans can also be used to precisely guide a biopsy needle
into a suspected metastasis. For this procedure, called a CT-guided
needle biopsy, the patient remains on the CT scanning table while a
radiologist advances a biopsy needle toward the location of the mass.
CT scans are repeated until the doctors are confident that the needle
is within the mass. (See the section, "Needle biopsy" below.)
CT scans take longer than regular x-rays. You will need to lie
still on a table, and the part of your body being examined is placed
within the scanner, a doughnut-shaped machine that completely surrounds
the table. The test is painless, but you may find it uncomfortable to
hold still in certain positions for minutes at a time. This is less of
a problem with modern scanners, which are much faster.
Magnetic resonance imaging (MRI)
MRI scans use radio waves and strong magnets instead of
x-rays. The energy from the radio waves is absorbed and then released
in a pattern formed by the type of tissue and by certain diseases. A
computer translates the pattern of radio waves given off by the tissues
into a very detailed image of parts of the body. Sometimes a contrast
material called gadolinium
is injected into your veins to better see the tumor.
MRI scans are often the best test for outlining a bone tumor.
They are also particularly helpful for looking at the brain and spinal
cord. MRI scans are a little more uncomfortable than CT scans. First,
they take longer -- often up to an hour. Also, you have to be placed
inside a tube, which is confining and can upset people with
claustrophobia (fear of enclosed spaces). The machine also makes a
thumping noise that you may find disturbing. Some places provide
headphones with music to block this out.
Radionuclide bone scan
This procedure helps show if a cancer has spread to other
bones. It can find metastases earlier than regular x-rays. Bone scans
also can show how much damage the primary cancer has caused in the
bone.
For this test, the patient receives an injection of
radioactive material called technetium diphosphonate. The amount of
radioactivity used is very low and causes no long-term effects. This
substance is attracted to diseased bone cells throughout the entire
skeleton. Areas of diseased bone will be seen on the bone scan image as
dense, gray to black areas, called "hot spots." These areas may suggest
metastatic cancer is present, but arthritis, infection, or other bone
diseases can also cause a similar pattern. To distinguish among these
conditions, the cancer care team may use other imaging tests or take
bone biopsies.
Positron emission tomography (PET or PET
scan)
PET scans use glucose (a form of sugar) that contains a
radioactive atom. A special camera can detect the radioactivity. Cancer
cells absorb high amounts of the radioactive sugar because of their
high rate of metabolism. PET is useful to look for cancer throughout
your body. PET scans can be more helpful than several different x-rays
because it scans the whole body. It can sometimes help tell if a tumor
is cancerous or benign. It is being combined with CT scans to better
pinpoint some kinds of cancer.
Biopsy
A biopsy
is a sample of tissue taken from a tumor so that it can be looked at
under a microscope. This is the only way to know that the tumor is
cancer and not some other bone disease. If cancer is present, the
biopsy can tell the doctor if it is a primary bone cancer or cancer
that started somewhere else and spread to the bone (metastasis).
Several types of tissue and cell samples are used to diagnose bone
cancer. It is very important that the biopsy procedure be performed by
a surgeon with experience in diagnosing and treating bone tumors.
The surgeon chooses a biopsy method based on whether the tumor
looks benign or malignant and exactly what type of tumor is most likely
(based on the bone x-rays, the patient's age, and the location of the
tumor). Some kinds of bone tumors can be recognized from needle biopsy
samples, but larger samples (from a surgical biopsy) are often needed
to diagnose other types. Whether the surgeon plans to remove the entire
tumor at the time of the biopsy will also influence the choice of
biopsy type. The wrong kind of biopsy may sometimes make it hard later
for the surgeon to remove all of the cancer without having to also
remove all or part of the arm or leg containing the tumor. It also may
cause the cancer to spread.
Needle biopsy
There are 2 types of needle biopsies: fine needle biopsies
and core needle biopsies.
For both types, a local anesthetic is first used to numb the area for
the biopsy. For fine needle aspiration (FNA), the doctor uses a very
thin needle attached to a syringe to withdraw a small amount of fluid
and some cells from the tumor mass. Often, the doctor can aim the
needle by feeling the suspicious tumor or area that is near the surface
of the body. If the tumor cannot be felt because it is too deep, the
doctor can guide the needle while viewing a CT scan. This is called a
CT guided needle biopsy and it is often performed by an x-ray
specialist known as an interventional radiologist. In a core needle
biopsy, the doctor uses a larger needle to remove a small cylinder of
tissue (about 1/16 inch in diameter and 1/2 inch long). Many experts
feel that a core needle biopsy is better than FNA to diagnose a primary
bone cancer.
Surgical bone biopsy
In this procedure, a surgeon needs to cut through the skin to
reach the tumor in order to remove a small piece of tissue. This is
also called an incisional biopsy. If the entire tumor is removed (not
just a small piece), it is called an excisional biopsy. These biopsies
are often done under general anesthesia (with the patient
asleep). They can also be done using a nerve block, which makes a large
area numb. If this type of biopsy is needed, it is important
that the
surgeon who will later remove the cancer be the one to do the biopsy.
Last Medical Review: 07/14/2009 Last Revised: 07/14/2009
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