Eosinophilic Granuloma

Definition

  • Condition at the benign end of the spectrum of histiocytosis X associated with unifocal or multifocal granulomas containing Langerhans cells & eosinophils

Terminology

  • Histiocytosis X comprises a spectrum of disorders.
    • EG
      • most benign. 
    • Hand-Schuller-Christian disease
      • exophthalmos, diabetes insipidus, & bone destruction
    • Letterer-Siwe syndrome
      • Most severe & potentially fatal
      • characterised by hepatosplenomegaly, lymphadenopathy, anaemia, acute infections & a downhill course

Epidemiology

  • First two decades of life
  • Slightly more common in males

Pathology

Eosinophilic Granuloma, histology of eosinophilic granuloma (langerhans cell histiocytosis)
Histology of eosinophilic granuloma (Langerhans cell histiocytosis). Image by No machine-readable author provided. KGH assumed (based on copyright claims)., Wikimedia Commons, CC BY-SA 3.0.
  • cell of origin is the Langerhans cell, a dendritic antigen presenting cell that is found all throughout the body, particularly in the skin & bones
  • Langerhans cell contains Birbeck granules, & has a nucleus with a deep cleft
  • Other cells found in the granulomas include eosinophils, PMNLs, giant cells, & mononuclear cells.  The Langerhans cells are arranged in clusters. 
  • Necrosis is very commonly seen
  • Grossly the lesion is soft, tan to reddish & occasionally greenish

Distribution

  • Skull, spine, pelvis & long bones, particularly the femur
  • Most commonly unifocal but may be multifocal – up to 50%
  • Has a preference for the skull & femur in children (sites of haematopoietic tissue) & the pelvis, ribs & skull in adults

Clinical

  • Commonest symptom is pain.  The pain is often worse at night
  • May be accompanied by a palpable mass, fever & a limited range of motion
  • Skin lesions are often seen

Investigations

Laboratory

  • Rarely helpful.  Occasional leukocytosis & elevated ESR.  Usually no eosinophilia

X-ray

Radiograph, ultrasound and MRI of an eosinophilic granuloma of the skull vault in an infant
Radiograph, ultrasound and MRI of an eosinophilic granuloma of the skull vault in an infant. Image by Hellerhoff, Wikimedia Commons, CC BY-SA 4.0.
  • XR typically shows lucent lesion sometimes with sclerosis. 
  • lesion is typically in the medullary canal of the diaphysis of a long bone
  • It can occur in the epiphysis, however, & cross open growth plates
  • It may cause cortical destruction
  • It is the great mimicker & is in the differential diagnosis of any skeletal lesion.  There may be expansion or periosteal reaction
  • In the spine causes vertebra plana

MRI

  • typically low T1 signal & high T2 signal.  Surrounding oedema

Differential Diagnosis

Treatment

  • For EG, treatment is usually observation & the tendency is for resolution.  Healing usually takes at least 5 months. 
  • If there is ongoing pain or a lesion in a weight bearing bone then intralesional corticosteroids or curettage & bone grafting is used
  • Radiotherapy can be used for inaccessible lesions

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.