title: [Langerhans cell histiocytosis and Erdheim-Chester disease, a continuity?]
abstract: BACKGROUND
  Erdheim-Chester disease and langerhans cell histiocytosis are two rare diseases separate on clinical, radiological and histological aspects. However, several cases involving both entities have been described.
  
  
  METHODS
  A 70-year-old man had a central diabetes insipidus, xanthelasmas, retroperitoneal fibrosis and osteosclerosis of the legs suggestive of Erdheim-Chester disease. Bone biopsy showed langerhans cell histiocytosis CD1a positive with the presence of BRAF V600E mutation. The patient was treated with vemurafenib with a good clinical course.
  
  
  CONCLUSIONS
  The literature review finds forty observations linking the two diseases that may suggest a pathophysiological link, especially with the hematopoietic myeloid stem cell CD34+. The term inflammatory myeloid neoplasm was advanced.
authors.affiliation: Service d'endocrinologie, hôpital du Cluzeau, 23, avenue Dominique-Larrey, 87042 Limoges cedex, France. Electronic address: simon.parreau@hotmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Parreau
authors.affiliation: Service de pathologie, hôpital de la Pitié-Salpétrière, AP-HP, 75013 Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Haroche
authors.affiliation: Service d'anatomopathologie, hôpital universitaire de Limoges, 2, avenue Matin-Luther-King, 87000 Limoges, France.
authors.forename: I
authors.initials: I
authors.lastname: Pommepuy
authors.affiliation: EA4340, « biomarqueurs en cancérologie et 7 onco-hématologie », université de Versailles, université Paris-Saclay, 78035 Versailles, France; Service de médecine interne 2, Centre national de référence maladies systémiques rares, groupe hospitalier Pitié-Salpêtrière, AP-HP, UMPC, université Paris-6, 47-83, boulevard de l'Hôpital, 75651 Paris, France.
authors.forename: J F
authors.initials: JF
authors.lastname: Emile
authors.affiliation: Service de radiologie, clinique François-Chénieux, 18, rue du Général-Catroux, 87039 Limoges, France.
authors.forename: J C
authors.initials: JC
authors.lastname: Bourras
authors.affiliation: Service d'endocrinologie, hôpital du Cluzeau, 23, avenue Dominique-Larrey, 87042 Limoges cedex, France.
authors.forename: F
authors.initials: F
authors.lastname: Archambeaud
mesh_terms: D000368:Aged; D018450:Disease Progression; D031249:Erdheim-Chester Disease / Q000150:complications* / Q000473:pathology; D006646:Histiocytosis, Langerhans-Cell / Q000150:complications* / Q000473:pathology; D006801:Humans; D008297:Male; D035583:Rare Diseases
keywords: BRAF; Erdheim-Chester disease; Histiocytose langerhansienne; Langerhans cell histiocytosis; Maladie d’Erdheim-Chester; Vemurafenib