Erdheim–Chester disease (ECD)

Summary
Description

Erdheim–Chester disease (also known as Erdheim–Chester syndrome or polyostotic sclerosing histiocytosis) is a rare disease characterized by the abnormal multiplication of a specific type of white blood cells called histiocytes, or tissue macrophages (technically, this disease is termed a non-Langerhans-cell histiocytosis). Usually, onset is in middle age. The disease involves an infiltration of lipid-laden macrophages, multinucleated giant cells, an inflammatory infiltrate of lymphocytes and histiocytes in the bone marrow, and a generalized sclerosis of the long bones

People and Age
ECD affects predominantly adults, with a mean age of 53 years
Benign or Malignant
Most Common Bones
Location in bone
Periosteal reaction
Position within the bone
Tumor density
Complete Information on this Tumor
Introduction and Definition

Erdheim-Chester disease is a rare systemic disorder, which is characterized by mononuclear infiltrate consisting of the lipid laden foamy histiocytes, which are found in various skeletal and extraskeletal organs. Most common sites involved are long bones,central nervous system, retroperitoneum, lung, heart, liver, spleen, skin and orbit. On histological examination there is infiltration of lipid laden histiocytosis within the connective tissues of the affected organ and positive with antibodies against CD68 on immunohistochemistry.

Incidence and Demographics
ECD affects predominantly adults, with mean age of 53 years
Symptoms and Presentation

Patients mostly present with pain in lower extremity. The involvement is usually bilateral and symmetrical. There is specific involvement of the appendicular skeletal, though involvement of the axial skeleton has also been reported. There can be associated general symptoms like fever, myalgia, weight loss, night sweats and flu like symptoms. The patient with systemic involvement can present with neurological symptoms, diabetes insipidus, exophthalmos, skin xanthomas and low back pain due to retroperitoneal fibrosis.

X-Ray Appearance and Advanced Imaging Findings
Bilateral and symmetric osteosclerosis of the diaphysis of the long bones is the most common radiological feature on plain X-ray. MR imaging shows the replacement of the normal fatty bone marrow by heterogeneous signal intensity on T1- and T2-weighted spin-echo images. Bone scan shows increase tracer uptake by the bone lesions.
Laboratory Findings
Anemia, increased creatinine, abnormal lipid profile, increased c-reactive protein and ESR
Differential Diagnosis
Langerhans’s cell histiocytosis,primary bone lymphoma,Pagets Disease and metastatic lesions
Preferred Biopsy Technique for this Tumor
Needle and open biopsy
Histopathology findings
Nodular area of lipid-rich foamy macrophages with hemorrhage, surrounded by fibrosis, thickened bony trabeculae, and minimal lymphocytic infiltrate
Treatment Options for this Tumor
Immunotherapy(interferon),systemic corticosteroid, Chemotherapy and immunosuppressant. Surgical debulking and radiation are also the options for mass lesions of the bone.
Outcomes of Treatment and Prognosis
The prognosis of Erdheim-Chester disease is poor due to extensive involvement of the vital organs and indefinite response to the treatment. Most patients die within two to three years after diagnosis due to congestive heart failure, lung fibrosis or renal insufficiency.
Suggested Reading and Reference
(1).Veyssier-Belot C, Cacoub P, Caparros-Lefebvre D, Wechsler J, Brun B, Remy M et al. Erdheim-Chester disease. Clinical and radiologic characteristics of 59 cases. Medicine 1996; 75(3):157-69 (2). "Erdheim–Chester Disease". ECD Global Alliance. http://www.erdheim-chester.org (3) Bancroft LW, Berquist TH. Erdheim-Chester disease: radiographic findings in five patients. Skeletal Radiol 1998;27:127–132 (4) Veyssier-Belot C, Cacoub P, Caparros-Lefebvre D, et al. Erdheim-Chester disease: clinical and radiologic characteristics of 59 cases. Medicine (Baltimore) 1996;75:157–169