title: [Expression of IgG4 in Rosai-Dorfman disease and its significance].
abstract: OBJECTIVE
  To study the prevalence of IgG4-positive plasma cells in Rosai-Dorfman disease and to assess the association between Rosai-Dorfman disease and IgG4-related sclerosing disease (IgG4-SD).
  
  
  METHODS
  The clinicopathologic features of 12 tissue samples of Rosai-Dorfman disease (11 extranodal and one nodal) from nine patients were reviewed. The degree of fibrosis and occlusive phlebitis was studied by HE staining. The expression of IgG4 and IgG in plasma cells were studied by immunohistochemistry (EnVision) and quantitatively analyzed by medical image analysis system.
  
  
  RESULTS
  Nine tissue samples showed different degree of fibrosis (four tissue samples were mild, one tissue sample was moderate and four tissue samples were severe) and two tissue samples showed occlusive phlebitis in the lesional tissue. Immunohistochemical study showed marked infiltration by IgG4-positive plasma cells (> 50 per high-power field) in four tissue samples, moderate infiltration (30 to 50 per high-power field) in two tissue samples, mild (10 to 29 per high-power field) in three cases and negative infiltration (< 10 per high-power field) in three tissue samples (P < 0.01). Three tissue samples fulfilled the diagnostic criteria of IgG4-SD (> 50 IgG4-positive plasma cells per high-power field and IgG4-to-IgG ratio > 40%), including one tissue sample each of Rosai-Dorfman disease in the left facial skin, above the left eye socket, and in the right parotid.
  
  
  CONCLUSIONS
  Some cases of Rosai-Dorfman disease fulfill the diagnostic criteria and show the histologic features of IgG4-SD. They may represent members of the IgG4-SD spectrum. The detection of IgG4-positive plasma cells in the lesional tissues of Rosai-Dorfman disease may have clinical pathological significance.
authors.affiliation: Department of Pathology, Taizhou Hospital, Taizhou 317000, China.
authors.forename: Qiupeng
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Pathology, Taizhou Hospital, Taizhou 317000, China; E-mail: Ganmf@enzemed.com.
authors.forename: Meifu
authors.initials: M
authors.lastname: Gan
authors.affiliation: Department of Pathology, Taizhou Hospital, Taizhou 317000, China.
authors.forename: Shouxiang
authors.initials: S
authors.lastname: Weng
authors.affiliation: Department of Pathology, Taizhou Hospital, Taizhou 317000, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.affiliation: Department of Pathology, Taizhou Hospital, Taizhou 317000, China.
authors.forename: Haihong
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Department of Pathology, Taizhou Hospital, Taizhou 317000, China.
authors.forename: Hansong
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Pathology, Taizhou Hospital, Taizhou 317000, China.
authors.forename: Caiping
authors.initials: C
authors.lastname: Xie
mesh_terms: D005355:Fibrosis; D015618:Histiocytosis, Sinus / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry*; D007150:Immunohistochemistry; D010689:Phlebitis / Q000473:pathology; D010950:Plasma Cells / Q000737:chemistry*
chemical_list: D007074:Immunoglobulin G