title: [Extranodal Rosai-Dorfman disease].
abstract: OBJECTIVE
  To investigate the diagnosis and differential diagnosis of extranodal Rosai-Dorfman disease.
  
  
  METHODS
  Two cases of extranodal Rosai-Dorfman disease were studied using hematoxylin-eosin, and immunohistochemical staining, along with a literature review.
  
  
  RESULTS
  The lesions of RDD were characterized by the presence of large histiocytes with emperipolesis, accompanied by infiltration of lymphocytes, plasma cells and other inflammatory cells. The large histiocytes had an abundant cytoplasm, pale to eosinophilic in appearance, positive for S-100 protein staining, with a vesicular nucleus and a small basophilic nucleolus in each cell.
  
  
  CONCLUSIONS
  Extranodal Rosai-Dorfman disease is known as an idiopathic proliferative disease of histiocytes with a distinct morphologic feature and is very rare. Differential diagnosis from other types of fibrohistiocytic proliferation lesions is recommended.
authors.affiliation: Department of pathology, Taizhou Hospital of Zhejiang Province, Linhai 317000, China. gmeifu@sohu.com
authors.forename: Mei-fu
authors.initials: MF
authors.lastname: Gan
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.forename: Xin-ru
authors.initials: XR
authors.lastname: Yu
authors.forename: Chun-kai
authors.initials: CK
authors.lastname: Yu
authors.forename: Hai-hong
authors.initials: HH
authors.lastname: Zheng
authors.forename: Ju-fang
authors.initials: JF
authors.lastname: Cai
mesh_terms: D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001921:Brain / Q000473:pathology / Q000601:surgery; D001927:Brain Diseases / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D062109:Dermatologic Surgical Procedures; D003937:Diagnosis, Differential; D015618:Histiocytosis, Sinus / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009418:S100 Proteins / Q000378:metabolism; D012867:Skin / Q000473:pathology; D012871:Skin Diseases / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D009418:S100 Proteins; C067980:CD68 antigen, human; D000097382:CD68 Molecule