Juvenile Xanthogranuloma

Clinical features

  • Infants and children. Approximately 20% are congenital, and more than 50% are diagnosed under 12 months
  • Benign solitary cutaneous lesion composed of histiocytes
  • Location-subcutaneous  or deep seated ( 5% of the cases)
  • In 4% of the cases systemic distribution is referred
  • Multiple lesions  in 12% of the cases
  • Upper part of the body (head, neck, upper trunk and extremities) is most commonly involved
  • Cases reported in eye, heart, bone and lungs are also reported, even though exceptional
  • Association with neurofibromatosis Type I or juvenile myelomonocytic leukaemia in rare cases , epilepsy, Nieman-Pick disease, urticaria pigmentar  and CMV infection

 

Fig 58 - Juvenile Xanthogranuloma –Numerous histiocytes in a loosely cohesive group, is simulating a granulomatous arrangement. Inflammatory cells dispersed in the background (H&E)
Fig 59 - Juvenile Xanthogranuloma –Loose population of histiocytes, polymorphonuclears and a multinucleated Touton giant cell (H&E)

 

  • Cellular smears, with vacuolated material in the background  ( Diff-Quick)
  • Loosely cohesive monotonous histiocytic cells
  • Oval nuclei, that can occasional bare a notch
  • Hypodense cytoplasm with occasional lipidic-like vacuoles
  • Lymphocytes, macrophages and polimorphonuclear cells (neutrophils and/or eosinophils in variable quantities)
  • Multinucleated cells, sometimes with Touton –like appearance
  • Necrosis can be present
  • Variable number of mitosis

 

Immunocytochemistry

  • CD68: Positive
  • Factor XIII: Positive
  •  Fascein: Positive
  • CD14: Positive
  • CD163: Positive
  • CD4: Positive  (occasional)
  • Vimentin: Positive ( focal )
  • S100-protein: Negative
  • CD1a: Negative

 

Modern Techniques of Diagnosis

  • Non-contributory

 

Differential Diagnosis

  • Granulomatous inflammatory lesions
    • The presence of mycobacterium or fungi must be excluded.
  • Langerhans ‘cell histiocytosis
    • Typical indented nuclei with a notch
    • CD1a and S100-protein are positive
    • Electron microscopy : Birbeck granules
  • Xanthoma
    • Typically associated with hiperlipidemia
    • Frequent cytoplasmic lipidic vacuoles

 

Main points

  • Pathogenesis remains uncertain- more probably a pseudoneoplastic condition
  • Histogenesis is still controversial- dermal dendritical cells?; plasmacytoid monocytes
  • Spontaneous regression over time, (1/3 before 6 months, 1/3 between 6 and 12 months and 1/3, between 12 months and three years 
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