title: Detection of malignant cells in serous body fluids by counting high-fluorescent cells on the Sysmex XN-2000 hematology analyzer.
abstract: BACKGROUND
  The body fluid mode of the Sysmex XN-2000 hematology analyzer differentiates cells into mononuclear and polymorphonuclear white blood cells (WBC) and high-fluorescent cells (HFC). The aim of this study was to evaluate the performance of the HFC count for detecting malignant cells in serous body fluids.
  
  
  METHODS
  Two-hundred and thirty serous fluids were analyzed on the Sysmex XN body fluid mode. HFC were measured as relative count (HFC/100 WBC) and absolute count (HFC/μL). All samples were microscopically screened on cytospin slides for the presence of malignant cells.
  
  
  RESULTS
  Malignant cells were found by microscopic examination in 49 of 230 samples (21.3%). Malignant samples contained significantly higher percentages (10.2 vs. 2.6/100 WBC) and absolute numbers (65 vs. 10/μL) of HFC than nonmalignant samples (P < 0.001). Areas under the ROC curve for relative and absolute HFC count were 0.69 and 0.77, respectively. A cutoff level of ≥17 HFC/μL showed the best performance to predict malignancy, with 88% sensitivity and 61% specificity.
  
  
  CONCLUSIONS
  As serous body fluids will be more analyzed on automated analyzers in the future, HFC count can be a useful tool to select samples for microscopic review. Microscopic evaluation should be performed if HFC values are above a certain threshold (e.g. ≥17 HFC/μL) or in case of clinical suspicion of malignancy.
authors.affiliation: Department of Laboratory Medicine, Imelda Hospital, Bonheiden, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Labaere
authors.affiliation: Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium.|Department of Oncology, Catholic University of Leuven, Leuven, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Boeckx
authors.affiliation: Department of Laboratory Medicine, Imelda Hospital, Bonheiden, Belgium.
authors.forename: I
authors.initials: I
authors.lastname: Geerts
authors.affiliation: Department of Laboratory Medicine, Imelda Hospital, Bonheiden, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Moens
authors.affiliation: Department of Laboratory Medicine, Imelda Hospital, Bonheiden, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Van den Driessche
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001826:Body Fluids / Q000166:cytology*; D005260:Female; D006801:Humans; D007958:Leukocyte Count / Q000295:instrumentation* / Q000379:methods* / Q000592:standards; D008297:Male; D008853:Microscopy / Q000379:methods; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000175:diagnosis*; D012372:ROC Curve; D015203:Reproducibility of Results
keywords: High-fluorescent cells; Sysmex XN; body fluid mode; malignant cells; serous body fluids