Recently, I had a patient come in for a Brain MRI. She had Erdheim-Chester disease. It is a type of histiocytosis. This disease is a rare non-Langerhans cells histiocytosis affecting multiple organ systems . Symmetric sclerosis of the long bones is usually reported, but the central nervous system and sinus can also be affected. Among patients with central nervous system involvement, the most frequent manifestations are diabetes insipidus, cerebellar syndromes, orbital lesions, and extra-axial masses involving the dura . The patient is coming in to be scanned about every 6 months. She is on cobalt and it seems to be helping. Her chemotherapy looks like it is making her very weak, but seems to be helping the disease. I was supprised at how little information there was about this disease on the web when I started looking. I did find one source of information that recomended doing a T2 flair cor in addition to the T2 flair ax. I am glad I did because the lesions in her brain show up better on the flairs than anything else.The lesions enhanced post gad but in a fuzzy sort of way. The flairs offer the best images in the study. Just my $.02.
Erdheim-Chester disease (ECD) is a rare multisystem disorder of adulthood. It is characterized by excessive production and accumulation of histiocytes within multiple tissues and organs. Histiocytes are large phagocytic cells (macrophages) that normally play a role in responding to infection and injury. (A phagocytic cell is any "scavenger cell" that engulfs and destroys invading microorganisms or cellular debris.) In those with ECD, sites of involvement may include the long bones, skin, tissues behind the eyeballs, lungs, brain, pituitary gland, and/or additional tissues and organs. Associated symptoms and findings and disease course depend on the specific location and extent of such involvement. The specific underlying cause of ECD is unknown.
68-year-old woman with Erdheim-Chester disease involving both lower extremities. Coronal T1-weighted MR image (TR/TE, 520/25) of both lower extremities shows diffusely invasive bone marrow masses destroying cortical bones in both tibias.
Erdheim-Chester disease, or ECD, is a potentially fatal disorder caused by the overproduction of histiocytes, which are large cells that help the body respond to infection or injury. These rogue histiocytes accumulate in the loose connective tissue, causing it to become thickened and dense. ECD can affect many areas of the body, including the eye cavity (orbit), skin, brain, long bones of the arm and leg and the lungs.
Numerous treatments have been attempted for this disease [2,6,13,14].
Corticosteroids are the traditional first-line treatment and are used to control
symptoms, but generally are either ineffective or only transiently effective [2,6].
Bisphosphonates are efficient in treating osteolytic lesions in Langerhans cell
histiocytosis but have only partial or temporary success in the management of bone
involvement in Erdheim-Chester disease . Chemotherapy can induce transient
partial responses, but is often ineffective [2,16]. Cladribine has been used
successfully in adult Langerhans histiocytosis, but its application in Erdheim-Chester
disease is limited to two patients, one of whom responded [16,17]. Radiation,
methotrexate, cyclosporine and azathioprine have not yielded sustained clinical
We describe the successful treatment of three patients suffering from Erdheim-
Chester disease with interferon-. The initial therapeutic dose of 3 to 6x106 units s.c.
three times per week, was reduced to 1x106 units three times per week because of
fatigue. This low dose was well tolerated and response was observed within one
month with dramatic reduction in the exophthalmos and recovery of vision in two
patients (case #1 and #3) whose vision was threatened by progressive disease while
on high-dose chemotherapy and/or steroids. Response was also manifested by
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gradual improvement in diabetes insipidus (cases #1 and #2) and in bone lesions
(case #2) (Figure 2).
The mechanism(s) underlying the salutary effects of interferon- in Erdheim-
Chester are unclear but could be due to several of the diverse biological effects of this
agent: maturation and activation of dendritic cells [9,10]; immune-mediated (e.g. via
natural killer cells) destruction of Histiocytes; or direct antiproliferative effects .
There is also anecdotal evidence of clinical therapeutic benefits for interferon-alpha in
other histiocytic disorders (Langerhans cell histiocytosis  and Rosai-Dorfaman
Erdheim-Chester disease is a rare and difficult-to-treat disease. All three of our
patients with this disorder achieved a long-lasting response (3+, 3.5 and 4.5+ years)
while receiving interferon-. Our observations suggest that this well-tolerated
treatment warrants further application and investigation in this disorder.(source)