!Juvenile Xanthogranuloma (JXG)

  • The most common histiocytic disease of childhood
  • 70% of cases appear during first year of life, 80% solitary
  • Clinical presentation
    • Head/neck > extremities, dome-shaped pink to orange/yellow/brown papules and nodules
    • Macronodular lesions
      • One or few 1-2cm nodules (>2cm giant)
    • Micronodular lesions
      • Many 2-5mm papules widely scattered upper body
  • Pathology
    • Dense infiltrate of histiocytes in superficial dermis, no Grenz
    • Xanthomatous appearance develops over time
    • Touton giant cells (abundant cytoplasm), foreign body giant cells possible
      • São histiócitos multinucleados com os núcleos à periferia em ferradura, destacam-se porque são espumosos
    • CD68, factor XIIIa positive, CD1a, S100 negative
  • Associations
    • Ocular JXG (uveal most common)
      • If ocular involvement is first, risk of skin lesions is lower (~40%)
      • <1% ocular risk if skin (solitary lesion) first
      • Ophtho screening for all children <2 with mutiple JXG (hyphema, uveitis)
    • Other visceral involvement rare
      • Lungs, heart, bones, central nervous system, pericardium, kidneys, digestive tract, liver, spleen, bone marrow, ovaries, testicles
    • JXG children monitored for NF-1 skin stigmata
  • Regress spontaneously at age 3-6 years
    • Adult cases persistent