Mycosis fungoides

    Article Contributors: 
    Sean Klepper M.D.
    Stephen Lyle, M.D., ...

    Clinical Features:

     

    • Indolent cutaneous T-cell lymphoma with a peak incidence in the fifth to seventh decades
    • Gradual progression over a number of years through three clinical stages: patch, plaque and tumor
    • If there is leukemic involvement, the term Sézary syndrome is used.

    Histologic Features:

     

    • Patch stage:
      • Usually scant perivascular, band-like or periadnexal infiltrate of small lymphocytes, often with atypia (described as "cerebriform")
      • Epidermotropism (tumor cells found within the epidermis): single cells and sometimes small collections
      • Haloes around the intraepidermal lymphocytes may be present.
      • Sometimes fibroplasia of the papillary dermis ("wiry collagen")
      • Superficial dermal edema and vascular proliferation may be present.
      • Absent to minimal spongiosis (helpful in the differential diagnosis with eczematous disorders, which may be indistinguishable from MF at this stage)
    • Plaque stage:
      • Dense band-like subepidermal infiltrate of neoplastic lymphocytes
      • More significant epidermotropism with occasional Pautrier microabscesses (punched-out spaces within the epidermis filled with neoplastic lymphocytes)
    • Tumor stage:
      • Dense, nodular proliferation of tumor cells filling the upper dermis and extending deeper than in earlier stages
      • There is often a significant decrease or loss of epidermotropism.
      • The lymphocytes acquire a more significant degree of atypia, with nuclear enlargement, greater irregularity of the nuclear contour and hyperchromia.
    • Immunophenotype: CD4+ (helper) T-cells (positive for CD2, CD3, CD5, CD7, CD45RO).
    • Loss of one or more pan-T-cell marker may occur and is supportive evidence for a neoplastic process.

    External Links

    Cases associated with this book:

  • Mycosis fungoides
    Author: Artur Zembowicz M.D. Ph.D.

    Conference: DermatopathologyConsultations.com Teaching Collection