Cutaneous non-Hodgkin lymphoma (NHL) which represent a heterogeneous group of T- and B-cell lymphomas.

• #2 M/C extranodal manifestation of NHL (M/C: GIT)

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Classification

WHO-EORTC classification:

• Cutaneous T-cell lymphomas (CTCL) (> 65%)
• Cutaneous B-cell lymphomas (CBCL) (25%)
• Unspecific (10%)

CTCL subtypes:

• Indolent CTCL subtypes:
  • Mycosis fungoides (MF) (M/C)
  • Other variants: Anaplastic large T-cell PCL, lymphomatoid papulosis, subcutaneous panniculitis-like T-cell lymphomas with alpha/beta T-cell phenotype, cutaneous lymphomas of T CD4+ cells of small and medium-sized pleomorphic cells
• Aggressive subtypes:
  • Sézary Syndrome (SS)
  • Others: PCL such as nasal-type T/NK-cell, T CD4- and CD8+ cells, unspecific T-cell and the T cell lymphoma/leukaemia of adults

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Aetiology

• Human T-cell lymphotropic virus type 1 (HTLV-1) (associated with Adult T cell leukaemia/lymphoma)