Mycosis Fungoides
Mycosis fungoides is a rare cutaneous T-cell lymphoma that often looks like an ordinary skin condition. This page explains what it is, why diagnosis can take years, how it affects the skin, and what living with it has meant for me.
Understanding the cancer I live with
Mycosis Fungoides
It has a name that sounds like a fungal infection, often begins by looking like an ordinary skin condition, and can take years to identify. Mycosis fungoides is actually a rare form of cutaneous T-cell lymphoma.
What it is
Cutaneous T-cell lymphoma
Where it begins
Primarily in the skin
What it is not
A fungal infection
First, That Ridiculous Name
Mycosis fungoides is one of those medical names that manages to be both intimidating and misleading. Despite the word mycosis and the distinctly fungal sound of the whole thing, there is no fungus involved. Mycosis fungoides is a cancer of T lymphocytes, a type of white blood cell, and it belongs to a group of diseases called cutaneous T-cell lymphomas, or CTCLs.
The cancerous T-cells are associated primarily with the skin, particularly early in the disease. That is why mycosis fungoides can spend years masquerading as a dermatological problem rather than announcing itself as lymphoma.
Cancer underneath.
This was one of the strangest things for me to get my head around. When most people hear the word lymphoma, they probably do not picture patches of irritated skin.
Mycosis fungoides does not always fit our mental picture of what cancer is supposed to look like, which is part of what makes it such an unusual disease to live with.
Why It Can Take So Long to Diagnose
Early mycosis fungoides can resemble much more common skin conditions. Patches may be red, scaly, itchy or eczema-like, and the appearance can change over time. That creates an obvious problem: eczema and psoriasis are common. Cutaneous T-cell lymphoma is not.
A biopsy is an important part of diagnosis, but even that is not always decisive the first time. Early disease can be difficult to distinguish under the microscope, and more than one skin biopsy may be needed before the diagnosis becomes clear.
That long diagnostic road matters
Someone can live with recurring skin problems for months or years before the pieces finally come together. That does not mean every persistent rash is lymphoma. It means mycosis fungoides can be exceptionally good at looking like something far less serious.
My own skin problems stretch back roughly fifteen years. Looking backward after receiving the diagnosis changes the way you remember a lot of those years.
What Mycosis Fungoides Can Look Like
There is no single appearance that defines the disease. Doctors commonly describe several types of skin involvement. A person may have one or more of them, and not everybody follows the same pattern or progresses through them in a neat sequence.
Patches
Flat areas of discoloured, reddened or scaly skin. These can resemble eczema and may persist or change over long periods.
Plaques
Areas of skin that become thicker, raised or more clearly defined than ordinary patches.
Tumours
More advanced skin involvement can include raised tumours. These may sometimes ulcerate or become vulnerable to infection.
Widespread Skin Changes
Some people develop extensive redness, scaling or itching involving large areas of the body.
Important: these descriptions are not a countdown. Mycosis fungoides behaves differently from one person to another, and having the disease does not mean someone will inevitably progress through every form of skin involvement.
How Doctors Work Out What Is Happening
Diagnosis and monitoring are not based on one magic test. Doctors can combine what they see on the skin with pathology, bloodwork and other testing depending on the circumstances.
The number, type and distribution of lesions can help show how much skin is affected and how the disease is behaving.
Tissue is examined by a pathologist for abnormal lymphocytes and other features associated with mycosis fungoides. Sometimes several biopsies are required.
Blood can be examined for abnormal cells and other changes, particularly when doctors need to determine whether the disease involves more than the skin.
Depending on the individual case, doctors may assess lymph nodes or use additional tests and imaging when they need to determine the extent of disease.
Mycosis Fungoides and Sézary Syndrome Are Related, but They Are Not the Same Thing
Both belong to the cutaneous T-cell lymphoma family, and the names are often discussed together. They are nevertheless distinct clinical diagnoses, and I think it is useful to understand the difference rather than treating the terms as interchangeable.
Mycosis Fungoides
Primarily associated with the skin
Mycosis fungoides commonly begins with skin involvement and can remain limited to the skin, although more advanced disease can involve lymph nodes, blood or internal organs.
Sézary Syndrome
Blood involvement is a defining feature
Sézary syndrome is another form of cutaneous T-cell lymphoma in which malignant T-cells are found in the blood. It is often associated with widespread redness, itching and scaling of the skin.
There Is No Single Treatment Plan
Treatment depends on how much of the skin is involved, whether the disease is found elsewhere, previous treatments, symptoms and how the disease is behaving. That means two people with the same diagnosis may receive very different treatment plans.
Skin-directed treatment
Depending on the situation, treatment can include topical medications, ultraviolet light therapy and radiation directed at affected areas of skin.
Systemic treatment
When treatment needs to work throughout the body, options can include medications such as retinoids, methotrexate, targeted therapies and immune-based treatments.
My own treatment has included methotrexate and acitretin, and I am now moving into treatment with mogamulizumab. I keep the changing details on the Treatment page.
What the Definition Does Not Explain
The medical definition of mycosis fungoides is fairly concise. Living with it is not.
A description of malignant T-cells does not explain what it is like to watch your skin change over years, to live with scars and discolouration, to wonder whether a new lesion matters, or to have the disease move from something managed in the background to something capable of reorganising your daily life.
It also does not explain the psychological oddness of having a cancer that is visible. My skin is not simply where the disease happens. It is the part of me I carry into every room.
That is why this site separates the medical information from the story without pretending they are completely separate things. One explains the disease. The other explains what it is like to live inside it.
Medical note: This page is intended to explain the disease I live with, not to diagnose anyone or replace medical advice. Persistent or unexplained skin changes should be discussed with a qualified healthcare professional.
Medical information on this page was checked against patient information from the National Cancer Institute and Lymphoma Canada.