title: Correlation of assessment of plasma cells by flow cytometry and detection of cytogenomic abnormalities by fluorescence in situ hybridization in plasma cell neoplasms.
abstract: BACKGROUND
  Increased monoclonal plasma cell count (PCC) in bone marrow (BM) is an indicator of a plasma cell neoplasm (PCN). Assessing PCC in BM by morphologic evaluation (ME) and flow cytometry (FC) is important in diagnosing PCN. Also important is fluorescence in situ hybridization (FISH) to detect cytogenomic abnormalities (CAs) in PCN. Owing to FC's short turnaround time, FC-assessed PCC is often used as empirical reference for further FISH study. However, correlation of FC-assessed PCs with FISH-detected CAs has not been well studied. The purpose of this study was to validate this correlation on BM aspirates from patients with PCN.
  
  
  METHODS
  We reviewed 224 cases of newly diagnosed PCN identified from our Lab-database. Both FC and FISH had been performed on BM aspirates from these cases, of which 178 had been assessed by ME. The original findings from the 224 cases were also reviewed.
  
  
  RESULTS
  Using a cut-off of 3% PCs assessed by FC as an indicator for further FISH analysis, 20 (17%) FISH-detectable PCN cases were missed; 30% of the missed cases carried high-risk CAs and/or were highly progressive PCN.
  
  
  CONCLUSIONS
  In PCN cases, an FC-assessed 3% PCC in BM aspirates should not be used as a cut-off for further FISH testing.
authors.affiliation: Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. gglu@mdanderson.org
authors.forename: G
authors.initials: G
authors.lastname: Lu
authors.forename: X X
authors.initials: XX
authors.lastname: Zhang
authors.forename: M J
authors.initials: MJ
authors.lastname: You
authors.forename: W
authors.initials: W
authors.lastname: Chen
mesh_terms: D000368:Aged; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology; D002869:Chromosome Aberrations; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism