title: Immunohistochemical analysis of CD123, CD56 and CD4 for the diagnosis of minimal bone marrow involvement by blastic plasmacytoid dendritic cell neoplasm.
abstract: OBJECTIVE
  Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive haematological malignancy derived from plasmacytoid dendritic cell precursors. Almost all patients show cutaneous manifestations, and >60% show bone marrow (BM) involvement at initial presentation. In cases where there is BM involvement by only a small number of tumour cells, such involvement is difficult to ascertain solely on morphological examination. In such situations, immunohistochemistry (IHC) may be useful in revealing minimal BM involvement by BPDCN.
  
  
  RESULTS
  We investigated six patients with BPDCN. Initial morphological diagnosis disclosed BM involvement in only one of the six patients. To confirm BM involvement, IHC for CD4, CD56 and CD123 was performed on BM biopsies or clot sections. IHC revealed minimal BM involvement (CD123, 3/3; CD56, 2/3; CD4, 2/3) in three patients with BM that appeared morphologically normal.
  
  
  CONCLUSIONS
  Our data clearly support the utility of IHC in diagnosing minimal BM involvement by BPDCN. Accordingly, we highly recommend immunohistochemical analyses for CD123, CD56 and CD4 in BPDCN patients, particularly in cases where the initial BM study indicates normal morphology.
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine , Seoul, Korea.
authors.forename: Keumrock
authors.initials: K
authors.lastname: Hwang
authors.forename: Chan-Jeoung
authors.initials: CJ
authors.lastname: Park
authors.forename: Seongsoo
authors.initials: S
authors.lastname: Jang
authors.forename: Hyun-Sook
authors.initials: HS
authors.lastname: Chi
authors.forename: Joo-Ryung
authors.initials: JR
authors.lastname: Huh
authors.forename: Je Hwan
authors.initials: JH
authors.lastname: Lee
authors.forename: Cheolwon
authors.initials: C
authors.lastname: Suh
authors.forename: Kyoo Hyung
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology*; D015704:CD4 Antigens / Q000378:metabolism; D019002:CD56 Antigen / Q000378:metabolism; D003713:Dendritic Cells / Q000378:metabolism / Q000473:pathology*; D005260:Female; D019337:Hematologic Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D053650:Interleukin-3 Receptor alpha Subunit / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor; D015704:CD4 Antigens; D019002:CD56 Antigen; C115022:IL3RA protein, human; D053650:Interleukin-3 Receptor alpha Subunit; C522918:NCAM1 protein, human