Sezary syndrome
Meaning of Sezary syndrome: The blood is what sets it apart: the same malignant cells circulate, so it behaves unlike a lymphoma confined to skin.
Definition of Sezary syndrome
Sezary syndrome is an aggressive cutaneous T cell lymphoma defined by three features together: widespread red, scaling, intensely itchy skin, enlarged lymph nodes, and malignant T cells circulating in the bloodstream. The skin is the most visible site, but the disease is not confined to it, and finding the circulating clone is what secures the diagnosis.
How does it differ from mycosis fungoides?
| Feature | Mycosis fungoides | Sezary syndrome |
|---|---|---|
| Skin | Patches and plaques, often for years | Redness over nearly the whole surface |
| Blood | Usually not involved | Malignant cells circulating, by definition |
| Course | Often indolent for a long time | Faster, with a poorer outlook |
| Standing | Commonest cutaneous T cell lymphoma | Classed separately as the leukemic form |
Both arise from the same family of mature T cells that home to skin, and the older idea that one simply turns into the other has been set aside. Most people with Sezary syndrome have no preceding history of patches and plaques, which is part of why the two are now treated as distinct entities rather than stages of a single disease.
What does it look like?
Redness covering most of the body surface is the hallmark, a state called erythroderma. The skin scales, thickens and itches to a degree that dominates daily life and sleep. Palms and soles crack, hair thins, nails ridge, and the lower eyelids can turn outward as the surrounding skin tightens. Losing heat through so much inflamed skin leaves people cold and shivering even in a warm room. Broken skin also lets bacteria in, so infection is a recurring feature of the illness rather than a separate misfortune.
How is it confirmed?
Appearance alone will not do it, because eczema, psoriasis and drug reactions can all redden the whole body. A skin biopsy is taken, but the decisive evidence comes from blood: counting the atypical T cell population, showing those cells share one receptor rearrangement, and demonstrating surface markers absent from healthy cells. That clone in the circulation is what separates the syndrome from a purely cutaneous lymphoma. The disease is a non-Hodgkin lymphoma of mature T cells, not a cancer arising from skin cells themselves.
Also known as
Used in a sentence
Flow cytometry of peripheral blood supported the diagnosis of Sezary syndrome.
Good to know
The malignant cells are lymphocytes that travel to the skin rather than skin cells themselves, so the disease is a lymphoma with skin involvement and not a form of skin cancer.