title: [Clinical and pathologic characteristics of Erdheim-Chester disease].
abstract: OBJECTIVE
  To explore the clinicopathologic features, immunophenotype, differential diagnosis and gene mutation status of the Erdheim-Chester disease (ECD).
  
  
  METHODS
  Clinical and pathologic findings of 3 ECD cases were examined by gross, microscopic, immunohistochemical methods and BRAF V600E mutation. Related literatures were reviewed.
  
  
  RESULTS
  Two male patients and one female patient presented clinically with multiple skin nodules, bone pain and bony lesions by imaging study. Microscopically, the lesions were composed of spindle-shaped fibroblasts, foamy histiocytes and scattered Touton-type giant cells embedded in reactive fibrous tissue. Lymphocytes, plasma cells, and multinucleated giant cells were also found. Immunohistochemically, all histiocytes were positive for CD68, none of which expressed CD1a, although 2 cases focally expressed weak S-100 stain. In 2 cases,BRAF V600E mutation was detected.
  
  
  CONCLUSIONS
  ECD is a rare disease of xanthogranulomatous histiocytosis.Its diagnosis relies on pathological and immunohistochemical findings, but correlation with clinical information, especially radiographic findings should be performed.No effective treatment of the disease is currently available.
authors.affiliation: Department of Pathology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing 100730, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Lu
authors.forename: Xinxin
authors.initials: X
authors.lastname: Cao
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Luo
authors.forename: Huacong
authors.initials: H
authors.lastname: Cai
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: E-mail: zhongdingrong@sina.com.
authors.forename: Dingrong
authors.initials: D
authors.lastname: Zhong
mesh_terms: D015703:Antigens, CD / Q000032:analysis*; D018949:Antigens, CD1 / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis*; D003937:Diagnosis, Differential; D031249:Erdheim-Chester Disease / Q000235:genetics / Q000276:immunology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation; D009418:S100 Proteins / Q000032:analysis; D016896:Treatment Outcome; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D018949:Antigens, CD1; D015214:Antigens, Differentiation, Myelomonocytic; D009418:S100 Proteins; C419393:CD1a antigen; C067980:CD68 antigen, human; D000097382:CD68 Molecule