Mycosis fungoides is a malignant T-cell lymphoma of the skin, first reported (and named) by Alibert (1835).
Sezary syndrome is a leukemic variant of mycosis fungoides defined by erythroderma with greater than 80% of the skin showing redness, adenopathy and greater than 1,000 circulating Sezary cells/microliter with a CD4+CD26- or CD4+CD7- phenotype. Sezary cells have a type 2 helper T cell cytokine profile. Sezary syndrome has a median overall survival time of only 2.4 years in patients with Sezary cells at a density of greater than 10,000 cells/microliter or 5.4 years in patients with 1,000-10,000 Sezary cells/microliter. Mycosis fungoides and Sezary syndrome are the most common cutaneous T-cell lymphomas. Sezary syndrome can arise de novo or can appear following years of chronic mycosis fungoides. Both are thought to arise from clonal expansion of CD4+ helper T cells responding to chronic antigen stimulation (summary by Wang et al., 2015). [from
OMIM]