Cutaneous T-Cell Lymphoma (CTCL, Mycosis Fungoides)

• T -cell neoplasm originating in skin; presentation varies based on stage of disease:
  • Patch stage: erythematous, violet or hyperpigmented patches (single or multiple) in sun-protected areas such as buttocks, thighs, abdomen
  • Plaque stage: well-demarcated irregularly shaped erythematous to violaceous to red-brown plaques in sun-protected areas; often pruritic and asymmetric; may arise de novo or from existing patches
  • Tumor stage: enlarging dome-shaped smooth nodules arising either de novo or from existing patches/plaques; aggressive with vertical growth
  • Sezary syndrome: triad of generalized lymphadenopathy, pruritic erythroderma, and Sezary cells (large hyperconvoluted lymphocytes); other symptoms often seen include alopecia, nail dystrophy, pruritus, and scaling of palms/soles
• Histology: epidermis may be acanthotic, atrophic or ulcerated, single cell exocytosis or epidermotropism of atypical lymphocytes into epidermis with Pautrier microabscesses (collection of atypical lymphocytes with cerebriform nuclei), diffuse or band-like mononuclear cell infiltrate with hyperchromatic cerebriform nuclei
• May need multiple biopsies before characteristic changes seen; atypical T cells typically negative for CD7 T-cell marker
• Treatment may be skin directed or systemic depending on stage of disease
  • Topical: corticosteroids or mechlorethamine (nitrogen mustard)
  • Phototherapy (PUVA, NBUVB)
  • Localized radiotherapy
  • Electron beam therapy
  • Photophoresis: typically for erythrodermic MF
  • Immunosuppressants: methotrexate, interferon-α
  • Bexarotene
  • Denileukin diftitox
  • Chemotherapy

Figure 5.12 A: CTCL, patch stage* B: CTCL, patch stage* C: CTCL, plaque stage* *Courtesy of Dr. Sophie M. Worobec

Figure 5.13 A: CTCL, tumor stage* B: Lymphomatoid papulosis* C: Lymphomatoid papulosis* *Courtesy of Dr. Sophie M. Worobec