What is Erdheim-Chester Disease?
Erdheim-Chester Disease (ECD) is a non-Langerhans Cell histiocytosis that usually affects adults. An extremely rare disorder, ECD can affect many different organs of the body and is difficult to diagnose. It is characterized by excessive production and accumulation of histiocytes, specific cells whose normal function is to fight infections. These cells accumulate in the loose connective tissue of the body. As a result this tissue becomes thickened, dense and fibrotic. Common symptoms can include fatigue, bone pain, protruding eyes (exophthalmos), reduced kidney function (increased creatinine), increased thirst (diabetes insipidus), fever, night sweats, balance issues (ataxia), slurred speech (dysarthria), retroperitoneal fibrosis, shortness of breath (dyspnea), cardiac issues, reduced sight and/or a rash.
Common symptoms and signs can include fatigue, bone pain, protruding eyes (exophthalmos), reduced kidney function (increased creatinine), kidney failure, increased thirst (diabetes insipidus), fever, night sweats, balance issues (ataxia), slurred speech (dysarthria), brain lesions, retroperitoneal fibrosis, ureter blockage, shortness of breath (dyspnea), cardiac issues, pericarditis, periaortic fibrosis (also known as "coated aorta"), pericardial infiltration with pericardial effusion. myocardial infiltration, atrial pseudotumour, reduced sight and/or a rash.
Multiple organs can be affected including the long bones of the legs and arms, skin, tissues behind the eyeballs, lungs, brain, pituitary gland, kidney, abdominal cavity, the membrane surrounding the heart, adrenal glands and more rarely, other organs. Some common signs include bilateral symmetric medullary sclerosis of the long bones; anemia; interstitial lung disease; intraconal masses; diffuse periaortic fibrosis (coated aorta); pericardial infiltration with pericardial effusion; myocardial infiltration; atrial pseudotumour; aortic and mitral valve disease; soft tissue masses; or brain lesions in the pons or cerebellum with T2 hyperintensity and often intense gadolinium enhancement. Unless successful treatment is found, organ failure can result. The cause of Erdheim-Chester Disease is unknown. It is not currently categorized as a cancer, infection or auto-immune disease. It has not been found to be contagious or genetic in nature. It can affect both men and women.
Diagnosis usually requires a tissue biopsy. ECD affected tissue will usually contain clusters of lipid-laden, foamy histiocytes, or granulomas, with signs of chronic inflammation and Touton-type giant cells, fibrosis and possible fat necrosis. The histiocytes express CD68 positive, CD1a negative, with S-100 protein expression variable and without Birbeck granules.
The ECD Global Alliance is a patient advocacy organization formed to provide help to those affected by ECD through support, awareness, education and research.