Sézary Syndrome

Sézary syndrome is a rare, fast-growing cancer that affects your skin and blood. At first, Sézary syndrome symptoms may look like eczema or other common skin issues. Healthcare providers can’t cure the condition, but they have treatments that can ease your symptoms and keep it from spreading from your skin and blood to other organs.


What is Sézary syndrome?

Sézary syndrome is a rare, fast-growing form of cutaneous T-cell lymphoma, a form of lymphoma that affects your skin. In Sézary syndrome, you have cancerous T lymphocytes (T-cells) in your skin, bloodstream and lymph nodes. The condition makes your skin change color, making it look red or darker than usual. It also causes a painful, itchy rash. The cancerous cells in your bloodstream may travel to other areas of your body. Healthcare providers have many ways to ease your symptoms, but there’s no cure for Sézary syndrome.

How common is Sézary syndrome?

It’s rare, affecting about 1 in 1 million people in the United States annually.


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Symptoms and Causes

What are the signs and symptoms of Sézary syndrome?

In Sézary syndrome, the most noticeable sign is a distinctive red rash (erythroderma) that itches a lot, hurts, peels and spreads quickly. (People of color may have patches of dark-colored skin that may look gray, purple or brown). Early on, Sézary syndrome symptoms look like eczema or psoriasis.

As Sézary syndrome gets worse, you develop small, raised bumps on your skin (papules). You may notice areas on your skin that feel harder or thicker than nearby skin (plaque). Eventually, you may develop tumors on your skin. Other signs and symptoms may include:

What causes Sézary syndrome?

Sézary syndrome happens when genetic mutations turn healthy T-cells into abnormal cells that multiply uncontrollably and eventually overpopulate the skin, lymph nodes and bloodstream. Experts aren’t sure what triggers the mutation.

What are the risk factors?

Being infected with human T-cell leukemia virus (HTLV) may increase your risk of developing Sézary syndrome.


What are complications of Sézary syndrome?

Sézary syndrome can affect your quality of life, making it hard to sleep and making you feel depressed or anxious. Other complications include:

Diagnosis and Tests

How is Sézary syndrome diagnosed?

Your healthcare provider will do a physical examination and evaluate your symptoms. They’ll ask about your medical history. If they think you have Sézary syndrome, they may do the following tests:

  • Blood tests, including a complete blood count (CBC) with differential, which includes checking the percentages of different white blood cells, a Sézary blood count to check the number of Sézary cells in your blood and a peripheral blood smear.
  • Your provider may do biopsies of your skin, lymph nodes or bone marrow.
  • A medical pathologist will study blood and tissue samples under a microscope. They’ll look for tumor markers and other changes in your cells that tell them more about what's going on.
  • If blood tests and lab tests show you have Sézary syndrome, your provider may perform tests to see if the cancer has spread. Tests may include chest X-ray, CT scans and positron emission tomography (PET) scan.


Management and Treatment

How is Sézary syndrome treated?

Your healthcare provider will recommend treatments based on your symptoms and the cancer stage. Treatments may include:

What are treatment side effects?

Most cancer treatments have side effects. Common chemotherapy and radiation therapy side effects include fatigue, nausea and vomiting. Phototherapy may affect your skin. Targeted therapy, immunomodulators and immunotherapy may cause diarrhea, rash and fatigue, and blood count abnormalities.

Outlook / Prognosis

Can Sézary syndrome be cured?

Unfortunately, there’s no cure for Sézary syndrome. But some treatments can help manage symptoms, keep abnormal cells from dividing and multiplying, and slow down how fast the cancer spreads.

How long does Sézary syndrome last?

Sézary syndrome is a chronic disease, meaning you’ll need treatment for the rest of your life.

What are Sézary syndrome survival rates?

About 24% of people with Sézary syndrome survive for at least five years after the disease develops. This rate will improve as new, more effective treatments appear. When you think about survival rates, remember, they’re estimates based on other people’s experiences.

Sézary syndrome is rare, making it difficult to gather enough information. If you have questions about your situation, ask your healthcare provider what you can expect.

Living With

How do I take care of myself?

Living with Sézary syndrome means receiving treatment for the rest of your life. You may need to take extra steps to protect your skin, like avoiding exposure to sunlight.

When should I see my healthcare provider?

Sézary syndrome symptoms may develop and change quickly. You should contact your provider if:

  • You see changes in your skin, like redness or darker-colored skin spreading to more areas of your skin, or small bumps becoming larger. These symptoms may mean your condition is getting worse.
  • You have frequent infections that take a long time to go away.

What questions should I ask my healthcare provider?

If you have Sézary syndrome, you may want to ask your healthcare provider:

  • What treatments are right for me?
  • What side effects can I expect from treatment?
  • Are there clinical trials I can take part in?
  • Can the cancer come back after treatment?

Additional Common Questions

What’s the difference between mycosis fungoides and Sézary syndrome?

Mycosis fungoides is another type of cutaneous T-cell lymphoma. It affects your skin, causing a red or dark-colored rash. Unlike in Sézary syndrome, people with mycosis fungoides don’t have significant numbers of cancer cells circulating in their bloodstream. But mycosis fungoides may eventually turn into Sézary syndrome.

A note from Cleveland Clinic

Sézary syndrome is a rare, fast-growing cancer that affects your skin and blood. It can spread to other areas of your body. At first, Sézary syndrome symptoms may look like eczema or other common skin issues. The difference is that Sézary syndrome symptoms rapidly get worse and don’t go away. Healthcare providers can’t cure the condition, but they have treatments that can ease your symptoms and keep the condition from spreading from your skin and blood to your organs.

Medically Reviewed

Last reviewed on 11/17/2023.

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