What is Erdheim-Chester Disease?

Request a Brochure


Erdheim-Chester Disease (ECD) is an extremely rare blood cancer that can affect many different organs of the body. It is characterized by excessive production and accumulation of specific cells whose normal function is to fight infections. These cells, called histiocytes, infiltrate the loose connective tissue of the body and cause inflammation. As a result, this tissue becomes thickened, dense, and fibrotic. If the disease is not treated, organ failure can result. In some patients, ECD may have a relatively benign course involving a limited number of organs, while in others, the disease could be more aggressive and may affect multiple organs including, but not limited to the bones, skin, heart, and brain. For this reason, it is important that ECD be properly treated and managed by a knowledgeable medical team that typically includes doctors across multiple specialties.

Who typically is diagnosed with ECD ?

The majority of ECD patients are typically diagnosed between the ages of 40-70 years, although there have been cases in children too. ECD can affect both men and women, with approximately 60% of reported cases occurring in men and 40% in women.

What causes ECD?

The exact cause of ECD is unknown. However, in 2016, the World Health Organization (WHO) categorized ECD as a type of blood cancer called histiocytic neoplasm. This recognition was due to the discovery of cancer-causing DNA changes (mutations) in the ECD tissues, specifically in the genes of the MAPK pathway, including BRAF, KRAS, MAP2K1, NRAS, etc. genes. The most common mutation is BRAF-V600E, which is found in 50-60% of ECD cases. These mutations are not believed to be in the DNA that parents transmit to their children, but rather in the cancer cells or blood cells.

What issues does ECD cause?

ECD can affect a variety of body parts, including the long bones of the legs, skin, the tissues behind eyes, lungs, brain, pituitary gland, kidney, abdominal cavity, the heart, blood vessels, adrenal glands, and more rarely other organs. The specific organs involved can vary from person to person; however, the most common presentation seen in over 90% of patients with ECD is the involvement of leg bones around the knees. Some patients might have only one affected organ, while others might have multiple affected organs. each individual can have different clinical signs and symptoms of ECD,depending on the degree and number of organs affected

Brief History

There have been a very limited number of published cases of ECD in the world since it was first described in 1930 by the Austrian pathologist, Jakob Erdheim and the American pathologist, William Chester. Since ECD is so rare and is not discussed in common medical textbooks, many doctors have never heard of it. It is also considered difficult to diagnose. For these reasons, most feel the disease is underdiagnosed. However, in recent years, as awareness grows, there seems to be an increasing number of diagnoses as awareness grows. Moreover, treatments have improved greatly with the discovery of MAPK pathway mutations which has led to the US-FDA approval of two targeted drugs, vemurafenib and cobimetinib, for patients with ECD

Current Efforts to Learn More

Most published articles on ECD were initially anecdotal in nature because studies were historically extremely difficult due to the small and geographically dispersed ECD patient population. However, a significant change began when patients and caregivers joined together to form the ECD Global Alliance. As part of this effort, ECD Referral Care Centers have been formed to provide comprehensive care for patients with ECD. There are several ongoing studies ranging from discovery of new treatments to improvement of symptoms and survivorship experience with this disease. The World Health Organization’s declaration of ECD as a blood cancer has enabled ECD better visibility, with improved opportunities to educate patients and their medical providers. Further, the American National Comprehensive Cancer Network has issued treatment recommendations and guidelines for ECD. This has made it possible for many medical providers to familiarize themselves with treatment strategies for ECD more easily.

What is the prognosis?

The prognosis for ECD is variable and depends mainly on the extent and distribution of the disease. It ranges from asymptomatic bone lesions to multi-systemic life-threatening forms. Due to the discovery of targeted therapies, the prognosis of ECD has improved significantly, both in terms of mortality (the rate of deaths) and morbidity (the rate of illness). It is important to note that there are patients with ECD who have been living high-quality lives for decades. While targeted therapies like vemurafenib and cobimetinib have made it possible to control ECD, they are not curative in nature. With these treatments, ECD has been converted to a chronic disease. Patients often struggle with side effects of treatment and/or long-term effects of their disease. The scientific field is evolving day by day, and more effective treatment strategies and guidelines to monitor patients effectively are hoped to be available in the near future.

Last updated: June 14, 2024

Contact Us

  • ECD Global Alliance, P.O. Box 775,
    DeRidder, LA 70634 USA

Featured Partners

Copyright 2024. All rights Reserved ECD GLOBAL ALLIANCE. A 501(c)(3) organization. EIN# 27-0759192. | Privacy Policy