Formerly known as histiocytosis x (eosinophilic granuloma, hand-schuller-christian disease, letterer-siwe disease)

• Due to proliferation of abnormal histiocytes (subtypes of WBC)

Clinical: Short stature, diabetes insipidus, neurosensory deafness and tooth mobility

Radiology: Osteolysis causing ’floating teeth’ in multiple quadrants

Histology:

• Diffuse infiltration of large, pale staining mononuclear cells with indistinct cytoplasmic
  borders rounded/bean shaped nuclei
• Birbeck granules: rod shaped cytoplasmic structures characteristic to Langerhans cells (s100 positive)

Management: Curettage of accessible bone lesions

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