ANSWER: Erdheim-Chester disease is a very rare disorder in which histiocytes, cells that help fight infection, multiply and infiltrate bone marrow and then spread throughout the body.
Erdheim-Chester disease is not a cancer, but histiocytes multiply and spread with the ferocity associated with an aggressive cancer. This progressive disease first affects the skeletal system, causing an abnormal increase in bone density and bone growths called lesions. Bone pain is often the first symptom, usually presenting in lower more often than upper extremities.
As the disease progresses, manifestations can be found in the nervous system, eyes, pulmonary system, heart, lymph nodes and kidneys. Symptoms can include:
- Changes in gait
- Changes in sensory ability
- Sleep disturbances
- Diabetes insipidus, a disorder characterized by intense thirst and by the excretion of large amounts of urine
- Vision problems
- Labored breathing or shortness of breath
- Heart failure
- Kidney damage
Given the wide range of symptoms and its rarity, the disease is easily misdiagnosed. Early on, Erdheim-Chester disease can be confused with Paget's disease, a condition that affects how bone breaks down and rebuilds.
A diagnosis of Erdheim-Chester disease can be confirmed with tissue or bone biopsies that show proliferation of histiocytes, cells that are normally inactive and immobile.
Treatment options are somewhat limited. Because the disease is rare, researchers and doctors simply haven't had the experience needed to find effective treatment options. Options used include chemotherapy, immunotherapy and corticosteroids.
Treatment can help delay progression of the disease for a time, but the outlook for patients with Erdheim-Chester disease isn't good. At five years, the overall survival rate is 41 percent.
If you or a family member is dealing with Erdheim-Chester disease, finding information or experienced care providers can be difficult. I've seen one patient with Erdheim-Chester disease in my career. Most doctors, even at large health care centers, will never see a patient with this condition. The ECD Global Alliance (www.erdheim-chester.org), a group formed by patients and families, can be a resource for you.—Erik Castle, M.D., Urology, Mayo Clinic, Arizona
(Medical Edge from Mayo Clinic is an educational resource and doesn't replace regular medical care. To submit a question, write to: email@example.com, or Medical Edge from Mayo Clinic, c/o TMS, 2225 Kenmore Ave., Suite 114, Buffalo, N.Y., 14207. For health information, visit www.mayoclinic.com.)