title: Comparison of plasma cell type of Castleman's disease and IgG4-related sclerosing disease: a histopathological and immunohistochemical study.
abstract: OBJECTIVE
  Castleman's disease (CD) is a group of rare atypical lymphoproliferative disorders classified as hyaline vascular (HV) and plasma cell (PC) types. CD may be closely mimicked by IgG4-related sclerosing disease (IgG4-SD) involving the lymph nodes. We retrospectively analyzed findings in patients with CD to elucidate the relationship between CD and IgG4-SD.
  
  
  METHODS
  Clinicopathological and immunophenotypical characteristics, including IgG+ and IgG4 expression by plasma cells, were analyzed in 87 consecutive patients diagnosed with CD from 1999 to 2010 at two major Korean hospitals.
  
  
  RESULTS
  The numbers of IgG+ (p < 0.001) and IgG4+ (p < 0.001) cells and the IgG4:IgG ratio (p = 0.003) were significantly higher in the PC than in the HV group. The mean IgG4+:IgG+ plasma cell ratio in the PC group was 25.1%, with 10 patients having a ratio >40%, the threshold IgG4:IgG ratio in patients with IgG4-SD.
  
  
  CONCLUSIONS
  Patients with the PC form of CD and IgG4-related lymphadenopathy share some features, including the pattern of plasma cell distribution and high-level infiltration of IgG4+ cells. Some patients thought to have the PC form of CD could be reclassified as showing IgG4-related lymphadenopathy.
authors.affiliation: Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea.
authors.forename: Jeong-Hyeon
authors.initials: JH
authors.lastname: Jo
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Park
authors.forename: Yoon Kyung
authors.initials: YK
authors.lastname: Jeon
authors.forename: Soo Jeong
authors.initials: SJ
authors.lastname: Nam
authors.forename: Jooryung
authors.initials: J
authors.lastname: Huh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005871:Castleman Disease / Q000145:classification / Q000175:diagnosis / Q000276:immunology* / Q000473:pathology*; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D007150:Immunohistochemistry; D008206:Lymphatic Diseases / Q000175:diagnosis / Q000276:immunology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000145:classification / Q000276:immunology / Q000473:pathology*; D012189:Retrospective Studies; D012598:Sclerosis; D055815:Young Adult
chemical_list: D007074:Immunoglobulin G