NCCN Guidelines for Patients
Mycosis Fungoides, Version 1.2016
Mycosis fungoides basics
Do I have mycosis fungoides?
At times, it may be useful to study the proteins
in the cells’ surface (membrane). This is called
immunophenotyping. It can support or confirm the
diagnosis that was made based on cell structure. An
hemistry) panel is a test for surface
proteins. It involves applying a chemical marker to
cells then looking at them with a microscope.
The IHC panel often tests for ßF1, CD2, CD3,
CD4, CD5, CD7, CD8, CD20, CD25, CD30, CD56,
granzyme B, TIA1, and TCR-CγM1. Mycosis
fungoides cells typically have ßF1, CD2, CD3, CD4,
and CD5 but not CD7, granzyme B, and TIA1. Cells
rarely have CD8. CD30 is found on at least a few
cells in most cases of mycosis fungoides. However,
up to half of people with large-cell transformed
mycosis fungoides have many cells with CD30.
If results from the skin biopsy aren’t clear, your blood
may be tested for Sézary cells. Your blood may also
be tested if your doctor suspects Sézary syndrome.
Sézary cells have one, round nucleus that is shaped
like the outer surface of the brain. Healthy people
may have a very small number of cells that look like
Sézary cells. People with mycosis fungoides may
have more. In Sézary syndrome, there is a very high
number of Sézary cells in blood.
Sézary cells have a common pattern of surface
proteins. Testing for this pattern is needed for
diagnosis since some cells look like Sézary cells.
Flow cytometry is a newer method of assessing
for surface proteins and should be used to test
for Sézary cells. The method first involves adding
a marker—a light-sensitive dye—to cells. Then,
your blood will be passed through a flow cytometry
machine. The machine measures surface proteins
on thousands of cells. To test for Sézary cells, flow
cytometry often includes CD3, CD4, CD7, CD8, and
A gene rearrangement is the fusion of one gene with
another gene to create a new gene. Often, mycosis
fungoides has rearrangements in the TCR (
eceptor) genes. PCR (
a test that can assess for TCR rearrangements. PCR
may be done on your skin cells, blood cells, or both.
This test may be helpful when cell structure and IHC
results do not clearly confirm mycosis fungoides.
irus) is important
for diagnosing a subtype of T-cell lymphoma. If you
have HTLV, the cancer may be adult T-cell leukemia
or lymphoma rather than mycosis fungoides. You
will need to be tested if your doctor thinks HTLV is
important for understanding your diagnosis.
Testing of HTLV is done on a blood sample. Serology
is a test that looks for antibodies that target HTLV. If
the results from serology are unclear, PCR can be
done. PCR is a process in which copies of a part of
DNA are made, which helps doctors find viruses.