Table of Contents

Sezary – low magnification

LEGEND

Histological findings closely resemble Mycosis Fungoides (MF). Clinico-pathologic correlation and additional blood investigations are required to confirm the diagnosis.

Criteria:

  • CD4:CD8 ratio > 10:1

  • Sézary cell count > 1000 cells/μL
  • Increased CD4+ T-cells with aberrant immunophenotypes: > 40% CD4+/CD7- or > 30% CD4+/CD26-

  • Monotonous infiltrate of atypical lymphocytes in the superficial dermis, often associated with fibrosis.

Sezary – low magnification

LEGEND

Normal or slightly acanthotic epidermis

  • Atypical lymphocytes are observed: they are large, with hyperchromatic nuclei.

    Epidermotropism is absent or minimal

Sezary

CD3 expression is strongly positive

Sezary

CD4:CD8 ratio > 10 :1

High CD4+ expression

Sezary

CD8 expression is significantly decreased.

Sezary

CD7 expression is often reduced or absent.