Sézary syndrome and mycosis fungoides: An overview, including the role of immunophenotyping

Abstract

This review discusses the definition and major categories of cutaneous T-cell lymphoma, Sézary syndrome and mycosis fungoides, and the role of immunophenotyping in their diagnosis. The following key points are raised: (a) Sézary syndrome and mycosis fungoides cells most often have a characteristic CD3+ CD4+ CD7− and/or CD26− immunophenotype. (b) This immunophenotype is not specific, but can assist in the distinction from non-neoplastic T cells and other subtypes of mature T-cell neoplasm.

International guidelines for the flow cytometric evaluation of peripheral blood for suspected Sézary syndrome or mycosis fungoides: Assay development/optimization, validation, and ongoing quality monitors

“…Optimal staining of T-cells is essential since the purpose of this flow cytometric assay is to detect a population of abnormal T-cells with an immunophenotype compatible with SS/MF (Pulitzer et al, 2021). The flow cytometric assay described in these guidelines detects abnormal T-cells using a difference from a normal approach.…”

“…In the past, clinical guidelines for SS/MF staging called for reporting the CD4/CD8 ratio and the relative proportion of the CD7 negative CD4+ T cells and CD26 negative CD4+ T cells. As discussed in the associated editorial and the previous articles in this series, the detection of neoplastic cells in the context of SS/MF is more successful when using a difference‐from‐normal approach that takes into account the composite phenotype (Craig, 2021; Horna et al, 2021; Pulitzer, Horna, & Almeida, 2021).…”

“…References specific for this assay : Please see this, and all other articles in this series on SS/MF (Craig, 2021; Horna et al, 2021; Pulitzer et al, 2021)…”

It is time to adopt a multicolor immunophenotyping approach to evaluate blood for Sézary syndrome and mycosis fungoides

“…Finally, recently developed guidelines for the validation of flow cytometric assays (Clinical Laboratory Standards Institute H62) (Clinical Laboratory Standards Institute, n.d.) will help laboratories design and implement reproducible assays that are able to reliably meet the assay requirements. This issue of the Journal includes four articles developed by an international group of experts, which address the required performance characteristics for a multicolor flow cytometry immunophenotyping assay for mycosis fungoides and Sézary syndrome and include practical guidelines for adoption (Pulitzer, Horna, & Almeida, n.d.; Guitart, n.d.; Illingworth et al, n.d.; Horna et al, n.d.). The first article describes the clinicians' perspective (Guitart, n.d.).…”

“…The first article describes the clinicians' perspective (Guitart, n.d.). The second article provides an overview of Sézary syndrome and mycosis fungoides, including the role of immunophenotyping (Pulitzer et al, n.d.). The third and fourth articles describe flow cytometric assay design and validation (Horna et al, n.d.; Illingworth et al, n.d.).…”