Erdheim-Chester disease

Etiology

likely a primary macrophage malignancy

Epidemiology

• average age 53 (range 21-76)
• M:F ratio 1:1
• world-wide 600-700 cases/year

Pathology

• retro-orbital masses
• fibrosis
• xanthogranulomas
  • predilection for long bones
  • plasma cells
  • giant cells
  • scattered lymphocytes
  • large foamy macrophages
• retroperitoneal fibrosis
• fibroinflammatory tissue surrounding the infrarenal aorta may result in renal failure
• diffuse interstitial pneumonia
• can affect CNS - > diabetes insipidus

Genetics

• BRAF V600E mutations (50%)

Clinical manifestations

• 42% asymptomatic
• proptosis
• blurry vision
• fatigue (case report)
• weight loss (case report)
• pericarditis (case report)
• renal failure (case report)
• night sweats (case report)
• bone pain, long bones
• cognitive impairment, depression (case report)

Laboratory

• biopsy, including bone marrow biopsy
• CD68 staining for macrophages
• BRAF V600E mutation

Radiology

• abdominal CT
• MRI neuroimaging - retro-orbital masses
• radiograph of long bones
  • bilateral osteosclerosis of metaphysis & diaphysis of long bones
• bone scintigraphy - characteristic pattern of uptake

Differential diagnosis

• Langerhans histiocytosis
• necrobiotic xanthogranuloma
• xanthoma disseminatum
• malignant histiocytosis
• Rosai-Dorfman disease
• IgG4-related disease

Management

• interferon alfa
  • generally 1st line
  • may exacerbate fatigue, depression
• anakinra if interferon alfa not advisable
  • beneficial for depression, fatigue (case report)
• vemurafenib (Zelboraf) for BRAF V600E mutation
  • use in conjunction with anakinra if depression, fatigue an issue (case report)
• treat pain
• prognosis: poor once disease affects lungs

More general terms

• histiocytosis