NCCN Guidelines for Patients
Melanoma, Version 1.2014
Blood tests are not used to find or confirm (diagnose)
melanoma. They may be used to monitor melanoma
once it has spread from the skin and lymph nodes
to other parts of the body. Abnormal levels of certain
chemicals in the blood may be a sign that the cancer
has spread to distant parts of the body. One of the
chemical levels that doctors look for is a high LDH
ydrogenase) level. LDH is a substance
found in the blood that is involved in energy
production in cells. If blood test results are abnormal,
your doctor may order other tests.
Imaging tests take pictures of the inside of your body.
Before the test, you may be asked to stop eating or
drinking for several hours. You should also remove
any metal objects that are on your body. Often there
are no side effects.
Imaging tests aren’t used to find (diagnose)
melanoma, but they may be used if you have signs
or symptoms that the melanoma has spread. Such
symptoms include pain that can’t be explained.
Imaging tests may also be given after treatment to
check that treatment worked. The imaging tests that
may be used for melanoma are described next.
A CT (
omography) scan takes many
pictures of a part of the body from different angles
using x-rays. As shown in Figure 8, a CT scan
machine is large and has a tunnel in the middle.
During the test, you will lie on a table that will move
slowly through the tunnel as the machine takes
many pictures. Then a computer will combine all the
pictures into one detailed picture. Imaging tests can
take 15 to 60 minutes to complete.
A computer combines the x-ray pictures to make
detailed pictures of organs and tissues inside the
body. Before the test, you may be given a contrast
dye to make the pictures clearer. The dye may be
put in a glass of water for you to drink, or it may
be injected into your vein. It may cause you to feel
flushed or get hives. Rarely, serious allergic reactions
occur. Tell your doctor if you have had bad reactions
Tests for melanoma
Blood tests | Imaging tests
Figure 8. CT scan machine
A CT machine is large and has a tunnel in the
middle. During the test, you will lie on a table that
moves slowly through the tunnel.