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Learning The Basics
Mycosis Fungoides (MF)
Mycosis fungoides is the most common form of CTCL. Because of that,
the terms MF and CTCL are often used interchangeably, and sometimes
imprecisely. For example, much of the research on MF reported in the
medical journals is listed under the name CTCL, even though MF is just
one type of CTCL. This can be a source of confusion. All cases of MF are
CTCL, but not all CTCL cases are MF. Mycosis fungoides can appear
anywhere on the body but tends to affect areas of the skin protected from
sun by clothing.
MF is an indolent type of CTCL, follows a slow, chronic course and very
often does not spread beyond the skin. Over time, in about 10% of cases, it
can progress to lymph nodes and internal organs. Symptoms of MF can
include flat, red, scaly patches, thicker raised lesions calls plaques, and
sometimes large nodules called tumors. The disease can progress over
many years, often decades.
Although there is continuing research, at this time no single factor has been
proven to cause this disease. There is no supportive research indicating
that it is genetic or hereditary. Studies have failed to show connections
between chemical exposure, environment, pesticides, radiation, allergies
and occupations. Exposure to Agent Orange may be a risk factor for
developing CTCL for veterans of the VietnamWar, but no direct cause-
effect relationship has been established.
While the number of new cases diagnosed each year is relatively low (about
3,000), it is estimated that, since patients have a very long survival, there
may be as many as 30,000 patients living with cutaneous lymphoma in
the United States and Canada. Due to the difficulty of diagnosing the
disease in its early stages and the lack of an accurate reporting system, these
numbers are estimates.
One of the challenges in describing this disease is that it doesn’t look the
same for all patients. Patches, plaques and tumors are the clinical names for
different skin manifestations and are generally defined as “lesions.” Patches
are usually flat, often scaly and look like a “rash.” Plaques are thicker, raised
lesions. MF patches and plaques are often mistaken for eczema, psoriasis or
“non-specific” dermatitis until an exact diagnosis is made.
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