title: The histiocytosis Erdheim-Chester disease is an inflammatory myeloid neoplasm.
abstract: Erdheim-Chester disease (ECD) is a rare, non-Langerhans histiocytosis, characterized by the infiltration of tissues by foamy CD68(+)CD1a(-) histiocytes. (99)Technetium bone scintigraphy revealing almost constant tracer uptake by the long bones is highly suggestive of ECD, and a 'hairy kidney' appearance on abdominal computed tomography scan is observed in about half of all ECD cases. CNS involvement is a strong prognostic factor and independent predictor of death. IFN-α seems to be the best initial treatment for ECD. More than half of all ECD patients carry the BRAF(V600E) mutation. More than 30 patients worldwide harboring this mutation and displaying multisystemic, refractory ECD have been treated with vemurafenib, a BRAF inhibitor, which has proven highly beneficial. Other recurrent mutations of the MAPK and PIK3 pathways (NRAS, PIK3CA) have recently been described. These mutations should lead to a new classification of histiocytic disorders such that Langerhans cell histiocytosis and ECD are classified as inflammatory myeloid neoplasms.
authors.affiliation: Department of Internal Medicine and French Reference Center for Rare Autoimmune and Systemic Diseases, Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Haroche
authors.forename: Fleur
authors.initials: F
authors.lastname: Cohen-Aubart
authors.forename: Frédéric
authors.initials: F
authors.lastname: Charlotte
authors.forename: Philippe
authors.initials: P
authors.lastname: Maksud
authors.forename: Philippe A
authors.initials: PA
authors.lastname: Grenier
authors.forename: Philippe
authors.initials: P
authors.lastname: Cluzel
authors.forename: Alexis
authors.initials: A
authors.lastname: Mathian
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Emile
authors.forename: Zahir
authors.initials: Z
authors.lastname: Amoura
mesh_terms: D031249:Erdheim-Chester Disease / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D006801:Humans; D007211:Indoles / Q000627:therapeutic use; D016898:Interferon-alpha / Q000627:therapeutic use; D009154:Mutation; D022423:Myeloid Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D009369:Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D048493:Proto-Oncogene Proteins B-raf / Q000037:antagonists & inhibitors / Q000235:genetics*; D013449:Sulfonamides / Q000627:therapeutic use; D016896:Treatment Outcome; D000077484:Vemurafenib
chemical_list: D007211:Indoles; D016898:Interferon-alpha; D013449:Sulfonamides; D000077484:Vemurafenib; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf
keywords: BRAF; Erdheim–Chester disease; Langerhans-cell histiocytosis; NRAS; PIK3CA; histiocytosis; interferon alpha; vemurafenib