Medically reviewed by Dr. A.M. van Coevorden, dermatologist
Mycosis fungoidesthe most common form of skin lymphoma, usually slow in course
Mycosis fungoides is a malignant proliferation of certain white blood cells (T cells) that occurs only in the skin. It is the most common form of skin lymphoma, with about 160 new patients a year in the Netherlands, usually over forty. It often begins with red, scaly, itchy patches and runs a slow course in most people.
What is mycosis fungoides?
Mycosis fungoides is a malignant proliferation of certain white blood cells (T cells), in which the abnormal cells are found only in the skin. The official name for skin cancer based on a proliferation of white blood cells is cutaneous lymphoma or skin lymphoma; that of mycosis fungoides is cutaneous T-cell lymphoma, mycosis fungoides type. In the Netherlands about 160 people a year develop a skin lymphoma, usually over forty, and mycosis fungoides is the most common form.
How do you get mycosis fungoides?
The basis for cancer lies in changes in the genetic material of cells. Why mycosis fungoides develops is not well understood.
What symptoms does it cause?
Usually red, scaly, itchy patches appear first, often five to twenty centimetres across, mainly on skin that gets no sun, such as the buttocks, trunk and thighs. Later the patches can thicken and become lumpy, and ulcers can form. In a small proportion of patients the disease spreads to the lymph nodes and eventually to internal organs.
Is it contagious?
No. Mycosis fungoides is not contagious.
How is the diagnosis made?
At first it is often not recognised and taken for eczema or psoriasis, which are far more common. This early stage with flat red scaly patches is called the patch stage; most patients stay in this stage. In some, the plaque stage with thicker patches develops after years, and in a small proportion the tumour stage with real lumps. To be sure, the doctor takes a piece of skin under local anaesthetic (biopsy); the pathologist then sees whether the abnormal cells lie in a band at the border of epidermis and dermis, which is characteristic. Further examination is usually only needed in the tumour stage or with enlarged lymph nodes.
What treatments are there?
Examination and treatment require specialist knowledge. Because the malignant cells are only in the skin, treatment is directed at the skin. Options are light therapy (PUVA, with UV-A after taking psoralens that make the skin more sensitive), bath PUVA, UV-B light therapy, hormone-containing creams (dermatocorticosteroids such as clobetasol) and applying cytostatics to the skin. Tumours can be irradiated, and with spread to lymph nodes or organs chemotherapy is sometimes used. These treatments usually do not cure the disease but reduce the symptoms.
Can mycosis fungoides be cured?
The outlook depends on the stage. Patients whose disease is found early and is still in an early stage have a good chance of long-term survival and usually little trouble. Treatment can make the skin lesions disappear completely, but lasting cure occurs in only about 10%. In most people the patches return, so maintenance treatment is needed; this can continue for years to decades without the disease becoming more serious. In the tumour stage or with spread to the lymph nodes the outlook is less good, although some people live with it for a long time. Regular check-ups are needed during and after treatment.
What can you do yourself?
Watch closely for signs that the disease is active. If something about your skin does not feel right, contact the dermatologist.
Frequently asked questions about mycosis fungoides
Is mycosis fungoides dangerous?
It is a form of skin cancer, but runs a slow course in most people. Those found early and staying in an early stage have a good chance of long-term survival.
Why is it confused with eczema?
Because it begins with red, scaly patches that resemble eczema or psoriasis, which are far more common. A biopsy gives certainty.
Will it ever go away completely?
Treatment can clear the patches, but lasting cure occurs in about 10%. In most people the patches return and maintenance treatment is needed.
Is it contagious?
No. It is a proliferation of your own white blood cells in the skin and does not pass from person to person.
What treatments are there?
Mainly skin-directed treatments such as light therapy (PUVA), hormone creams and topical chemotherapy; tumours can be irradiated.