title: Clusterin expression in cutaneous CD30-positive lymphoproliferative disorders and their histologic simulants.
abstract: BACKGROUND
  Clusterin is a ubiquitous 80 kDa heterodimeric glycoprotein previously shown to be expressed on tumor cells of systemic and, to a lesser extent, primary cutaneous anaplastic large cell lymphoma (PC-ALCL). Lymphomatoid papulosis (LyP), an important differential diagnosis of ALCL, has been studied for clusterin expression in only a small number of cases. The aim of this study was to compare clusterin immunostaining patterns in LyP and other cutaneous histologic simulants with those of PC-ALCL.
  
  
  METHODS
  Formalin-fixed, paraffin-embedded sections of PC-ALCL (6), LyP (20), mycosis fungoides with large cell transformation (MF-LCT, 12), pityriasis lichenoides et varioliformis acuta (PLEVA, 12), arthropod bite reaction (ABR, 12) and lymphomatoid reactions (LR, 9) were immunostained for clusterin and evaluated for staining pattern and distribution. All diagnoses were made with clinicopathologic correlation.
  
  
  RESULTS
  Characteristic dot-like Golgi staining was identified in 10/20 LyP (50%), 4/6 PC-ALCL (67%) and 9/12 MF-LCT (75%). Two of 12 PLEVA (17%), 1 of 12 ABR (8%) and 2 of 8 LR (25%) had lymphocytes (< 25%) with diffuse cytoplasmic staining. Dermal dendritic cells stained strongly for clusterin. High background staining occurred in some cases.
  
  
  CONCLUSIONS
  Clusterin immunostaining does not reliably distinguish between LyP, PC-ALCL or MF-LCT, but could distinguish LyP from its reactive histologic simulants.
authors.affiliation: Department of Pathology, University of Michigan Medical Center, Ann Arbor, MI 48109-0602, USA.
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Olsen
authors.forename: Linglei
authors.initials: L
authors.lastname: Ma
authors.forename: Bertram
authors.initials: B
authors.lastname: Schnitzer
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Fullen
mesh_terms: D051152:Clusterin / Q000096:biosynthesis*; D003713:Dendritic Cells / Q000378:metabolism / Q000473:pathology; D020405:Dermis / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006056:Golgi Apparatus / Q000378:metabolism / Q000473:pathology; D006801:Humans; D017730:Ki-1 Antigen; D016410:Lymphoma, T-Cell, Cutaneous / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D009363:Neoplasm Proteins / Q000096:biosynthesis*
chemical_list: C495242:CLU protein, human; D051152:Clusterin; D017730:Ki-1 Antigen; D009363:Neoplasm Proteins