Mycosis Fungoides

checkorphan

Overview

Mycosis fungoides (pronounced “my-KOH-sis fun-GOY-deez”) is a blood cancer that happens when white blood cells called T cells transform into malignant (cancer) cells. T cells are a kind of lymphocyte. Lymphocytes fight harmful pathogens in your body, like viruses and bacteria. With mycosis fungoides, T cells transform into cancer cells that affect your skin.

Mycosis fungoides is a type of cutaneous T-cell lymphoma (CTCL). CTCL is a group of rare blood cancers that cause changes in your skin, like itchiness, rashes, plaques or tumors.

Although mycosis fungoides affects your skin, it’s not a form of skin cancer because your T cells — not skin cells — become cancerous.

Symptoms

Mycosis fungoides symptoms occur in several stages of skin changes. Not everyone progresses through all the phases. Some may happen simultaneously.

For many people, the first sign of disease in the early stage is a mycosis fungoides rash. Mycosis fungoides stages include:

  • Premycotic phase: A scaly skin rash forms. It appears on parts of your body not usually exposed to the sun, like your lower belly, thighs, butt and breasts (chest).
  • Patch phase: The skin around the rash becomes thin. It may be itchy and dry, like eczema.
  • Plaque phase: Your skin forms small, raised bumps or hard bumps.
  • Tumor phase: Tumors, raised areas of skin that penetrate more deeply than plaques, form on your skin. The most common locations include your thighs, groin, armpits and the inside of your elbow. The tumors may develop ulcers and get infected.

In the most severe stages, many cancerous T cells circulate in your blood. At this point, they’re called Sézary cells. High levels of Sézary cells may cause mycosis fungoides to evolve into Sézary syndrome. With this condition, you may develop a red rash all over your body, called erythroderma.

Causes

Experts don’t know what causes mycosis fungoides, but genetic mutations may play a role. Genetic mutations are changes in the genetic material inside a cell, like DNA or chromosomes. Many people with mycosis fungoides have missing genetic material or errors in the genetic material inside the cells that become malignant.

These genetic mutations don’t seem to be inherited (passed down through families).

Researchers continue to study other potential causes, such as exposure to certain environmental toxins and infections.

Mycosis fungoides isn’t contagious. It doesn’t spread from person to person.

Prevention

There’s no proven way to prevent mycosis fungoides. You can reduce the risks of late-stage mycosis fungoides by scheduling regular appointments with a healthcare provider. Regular checkups can increase the chances of detecting mycosis fungoides in its early stages.

Perform monthly skin self-checks for rashes, moles or other changes. If you notice any skin changes, schedule an appointment with a dermatologist.

Diagnosis

It may be challenging to diagnose mycosis fungoides based on a visual skin exam because it can resemble other skin conditions. It’s easy to mistake mycosis fungoides for more common skin conditions during an exam, like eczema or psoriasis.

To confirm or rule out mycosis fungoides, your healthcare provider will likely perform additional tests such as:

  • Skin biopsy or lymph node biopsy: A procedure that removes tissue from the affected area so a pathologist can test the tissue in a lab for signs of mycosis fungoides. You may need multiple biopsies to locate evidence of the tumor cells associated with mycosis fungoides.
  • Blood tests: Your healthcare provider may look for changes in your blood cells and chemical markers (like enzymes) that may be signs of mycosis fungoides.
  • Imaging procedures: Your healthcare provider may look for signs that the cancer has spread to your lymph nodes or organs other than your skin. Imaging procedures may include a CT scan or PET scan.

Prognosis

The prognosis depends on multiple factors, with cancer stage being especially important.

It’s much easier to treat mycosis fungoides in its early stages. Many people who receive early diagnosis and treatment experience long periods with no symptoms.

More advanced mycosis fungoides may need more intensive treatment. For example, you may need radiation therapy or chemotherapy if cancer has spread beyond your skin.

What is the life expectancy of someone with mycosis fungoides?

The 10-year survival rate for early-stage mycosis fungoides is 95%. The life expectancy for advanced mycosis fungoides is three to five years, and it may be less if the cancer has spread beyond your skin.

Still, it’s important to remember that these numbers are just statistics. Your prognosis depends on various factors unique to you, including age, overall health and disease course. Your healthcare provider is your best resource for answering questions about what to expect with mycosis fungoides, including likely treatment outcomes and life expectancy.

Treatment

Mycosis fungoides treatment depends on the cancer stage and type of skin changes. Many treatment options focus on relieving symptoms and improving your quality of life.

Your healthcare provider may prescribe:

  • Skin-directed therapy: Topical gels, steroids, retinoids or ultraviolet (UV) light (phototherapy) treat cancer on affected areas of your skin. With psoralen-ultraviolet A therapy (PUVA), a healthcare provider combines a pill (psoralens) with UV light to destroy cancer cells on your skin. Your provider may also use a topical chemotherapy drug, such as mechlorethamine (Valchlor®).
  • Systemic therapy: Medicines such as bexarotene (Targretin®) or methotrexate (Rheumatrex®, Trexall®) can treat your whole body. Other classes of drugs include Interferon α and histone deacetylase (HDAC) inhibitors. Intravenous medicines (taken through your vein) include chemotherapy, such as gemcitabine (Gemzar®), pegylated liposomal doxorubicin or pralatrexate (Folotyn®).
  • Immunotherapy: Immunotherapy boosts your immune system so it’s better at identifying and attacking cancer cells.
  • Monoclonal antibodies as targeted therapy: These medicines detect and destroy cancer cells. Healthcare providers may use targeted therapy if your body hasn’t responded to other systemic therapy. Treatments include mogamulizumab-kpkc (POTELIGEO®) and brentuximab vedotin (Adcetris®).
  • Radiation therapy: With radiation therapy, strong beams of energy from outside your body destroy cancer cells or stop their growth.

Healthcare providers rarely use traditional chemotherapy for mycosis fungoides. Chemotherapy doesn’t always effectively treat mycosis fungoides. It also carries a significant risk of side effects.