Cellular Classification of Mycosis Fungoides and the Sézary Syndrome

The histologic diagnosis of mycosis fungoides and the Sézary syndrome (MF/SS) is usually difficult to determine in the initial stages of the disease and may require the review of multiple biopsies by an experienced pathologist.

A definitive diagnosis from a skin biopsy requires the presence of MF/SS cells (convoluted lymphocytes), a band-like upper dermal infiltrate, and epidermal infiltrations with Pautrier abscesses (collections of neoplastic lymphocytes). A definitive diagnosis of SS may be made from a peripheral blood evaluation when skin biopsies are consistent with the diagnosis. Supportive evidence for circulating Sézary cells is provided by T-cell receptor gene analysis, identification of the atypical lymphocytes with hyper-convoluted or cerebriform nuclei, and flow cytometry with the characteristic deletion of cell surface markers such as CD7 and CD26. However, none of these is individually pathognomonic for lymphoma. [1,2]

References

1. Olsen EA, Rook AH, Zic J, et al.: Sézary syndrome: immunopathogenesis, literature review of therapeutic options, and recommendations for therapy by the United States Cutaneous Lymphoma Consortium (USCLC). J Am Acad Dermatol 64 (2): 352-404, 2011.  [PUBMED Abstract]
   
   
2. Fraser-Andrews EA, Russell-Jones R, Woolford AJ, et al.: Diagnostic and prognostic importance of T-cell receptor gene analysis in patients with Sézary syndrome. Cancer 92 (7): 1745-52, 2001.  [PUBMED Abstract]