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Langerhans Cell Histiocytosis

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Langerhans Cell Histiocytosis, Multifocal Eosinophilic Granuloma, Hand Schüller Christian Syndrome, Histiocytosis X

  • Epidemiology
  1. Rare Prevalence: 4 to 5 per 1 Million Children
  • Precautions
  1. Exercise caution in age <3 years presenting with atypical, refractory skin lesions (often misdiagnosed initially)
  • Pathophysiology
  1. Rare group of disorders with proliferation of Langerhans Cells (White Blood Cell subtype)
    1. Originates in the Bone Marrow from progenitor cell proliferation of myleoid Dendritic Cells
  2. Lesions infiltrate bones (80% of cases, esp. skull), skin, lung and in some cases the Pituitary Gland
  3. Most often presents in childhood, especially infancy, with atypical skin lesions mistaken for other conditions (e.g. Eczema)
  4. Oncogenic mutation BRAF V600E found in 64% of cases
  • Symptoms
  1. Fever
  2. Atypical rash (see below)
  • Findings
  1. Multisystem findings in >87% of patients with skin lesions
    1. Acute disseminated multisystem disease is more common in age <3 years
  2. Atypical skin lesions
    1. Seborrhea-like lesions
      1. Scaly red-brown Papules
    2. Eczema-like lesions
      1. Erythematous, scaly lesions on scalp, flexor folds
    3. Petechiae, Purpura or hemorrhagic crusts
  3. Bone lesions (80% of cases)
    1. Skull is most often affected
  4. Hematologic
    1. Lymphadenopathy
    2. Hepatomegaly
    3. Splenomegaly
  • Diagnosis
  1. Lesion biopsy
  • Prognosis
  1. Multisystem disease
    1. More common in age <3 years
    2. Worse prognosis if involvement of liver, Bone Marrow or Spleen (five year survival 77%)
  2. Single organ involvement
    1. More common in age >3 years old
    2. Better prognosis with five year survival approaching 100%