By Gary M. White, MD

Sézary syndrome

Sézary syndrome (SS) may be thought of as "Diffuse erythroderma of CTCL". It is characterized by erythroderma, the presence of circulating malignant T-cells in the peripheral blood and generalized lymphadenopathy.

The adult with diffuse erythroderma may have erythrodermic CTCL. It can develop de novo or as a progression of more typical CTCL. The disease may rapidly progress to involve the lymph nodes and blood or it may progress slowly over years. There has been some controversy as to the exact definition of the Sézary syndrome. One paper proposed the following criteria: generalized erythroderma, compatible skin histology, more than 5% circulating atypical mononuclear cells and evidence of a peripheral blood T-cell clone [JAAD 1999;41;254]. Given this definition and in an analogous fashion to above, patients may develop Sézary syndrome de novo or as a progression of more typical CTCL. Circulating interleukin-2 appears to be a reliable indicator of disease activity in Sézary syndrome. Routine blood films may show large "Sézary cells" 15-20 um in diameter.

In one study of the earliest skin manifestations of SS before erythroderma set in [JAAD 2017;77;719], patients were described as having a nonspecific dermatitis [49%], atopic dermatitis-like eruption [4.9%] or patches and/or plaques of CTCL [11%] (not all patients could be classified due to lack of clinical information).

Of note, a variant of Sézary syndrome without erythroderma occurs [JAAD 2015;72;1003]. These patients usually present with chronic pruritus. They satisfy hematologic involvement criteria, but lack visible skin changes.

The risk of development of secondary malignancy has been studied [AD 1999;135;1381]. Of 71 patients, 16 (23%) developed malignancies. Specifically, 10 squamous cell carcinoma and 9 internal malignancies were found. The incidence of SCC was 42 times that of the normal population. The development of malignancy did not seem related to treatment and thus is thought related to the disease itself.


Referral to an oncologist is appropriate. See CTCL

Brentuximab vedotin demonstrates significant clinical activity in relapsed or refractory mycosis fungoides with variable CD30 expression [JAMA Derm Feb 2014].

Uncertain Cases

When the diagnosis is uncertain, e.g. between psoriasis and Sézary syndrome, one can use therapy good for both, e.g. topical steroids, nbUVB, PUVA, methotrexate or acitretin.


Homepage | FAQs | Contact Dr. White

It is not the intention of RegionalDerm.com to provide specific medical advice, diagnosis or treatment. RegionalDerm.com only intends to provide users with information regarding various medical conditions for educational purposes and will not provide specific medical advice. Information on RegionalDerm.com is not intended as a substitute for seeking medical treatment and you should always seek the advice of a qualified healthcare provider for diagnosis and for answers to your individual questions. Information contained on RegionalDerm.com should never cause you to disregard professional medical advice or delay seeking treatment. If you live in the United States and believe you are having a medical emergency call 911 immediately.