Lentigo Maligna

• Lentigo Maligna
  • Is slowly evolving in-situ disease
    • Hutchinson’s melanotic freckle
    • Large irregular/asymmetric macular lesion
    • Can be present for decades before invasion
    • Blue-black flat lesion, or amelanotic
• Progression
  • Lentigo Maligna Melanoma
    • Invasive disease (5%) often occurs
      • On the face
      • In elderly with other signs of sun exposure
    • Least malignant potential of melanomas
• Histology
  • Diffuse continuous replacement of basal layer
    • Spindle-shaped cells
    • Lack of Pagetoid cells
• Diagnosis
  • Excision or incisional biopsy
    • If Lentigo Maligna Melanoma then treat as for Melanoma
• Treatment
  • Cosmetically challenging, may require 2 stage procedure
    • High recurrence rates after excision
  • Treatment options:
    • Surgical Excision – ideal margin 5-10mm
    • Radiotherapy
    • Cryotherapy
    • Imiquimod – not yet fully evaluated
• Prognosis
  • Good, 5-20 yrs or longer