Diagnostic DNA-flow- vs. -image-cytometry in effusion cytology

Our plain-English summary of Diagnostic DNA-flow- vs. -image-cytometry in effusion cytology, by H. Motherby, N. Pomjanski, M. Kube, et al (Analytical Cellular Pathology, 2002).

The study

• Authors: H. Motherby, N. Pomjanski, M. Kube, A. Boros, T. Heiden, B. Tribukait, A. Böcking
• Journal: Analytical Cellular Pathology
• Published: 2002;24(1):5-15
• Cited by: 24 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Aims: To determine the sensitivity and specificity of flow- and image-cytometry for the detection of DNA-aneuploidy as a marker for malignant cells in effusions.

Methods: 200 effusions (80 tumor cell-positive, 74 negative and 46 cytologically equivocal) were stained with DAPI-SR for DNA-flow- and with Feulgen-Pararosaniline for -image-cytometry. They were measured using a PAS-flow-cytometer and an AutoCyte-QUIC-DNA-workstation according to the ESACP consensus reports for DNA-flow- and -image-cytometry, respectively [7,23,29,49].

Results: Sensitivity of DNA-aneuploidy for the identification of malignant cells was 32.1% for DNA-flow- and 75.0% for -image-cytometry, specificity of -euploidy in benign cells was 100.0% for both methods. Positive predictive value of DNA-aneuploidy for the identification of malignant cells was 100.0% for both techniques, negative predictive value of DNA-euploidy was 48.6% for DNA-flow- and 72.0% for -image-cytometry.

Conclusions: Searching for DNA-aneuploidy as a diagnostic marker for neoplastic cells in serous effusions image-cytometry revealed superior sensitivity as compared with monoparametric flow cytometry.

In plain English

This study, from Heinrich-Heine-University in Düsseldorf, compared two laboratory methods for measuring cell DNA content, DNA flow cytometry and DNA image cytometry. The aim was to detect cancer cells in fluid from the body cavities (effusions). The authors tested 200 effusions examined routinely between April and October 1998: 80 judged tumor cell-positive by standard cytology, 74 negative and 46 equivocal. Asbestos exposure was not studied. Neither method found abnormal DNA content (aneuploidy) in benign effusions. Among the 80 tumor cell-positive effusions, 47 were aneuploid by flow cytometry and 70 by image cytometry. Of the six malignant mesotheliomas among them, three and four were aneuploid, respectively. In the 46 equivocal effusions, sensitivity was 32.1% (9 of 28 found to be malignant) for flow and 75.0% (21 of 28) for image cytometry; specificity was 100.0% (18 of 18 found to be benign) for both. Total diagnostic accuracy was 74.0% and 91.5%. The authors concluded that image cytometry had higher sensitivity than the monoparametric (single-parameter) flow cytometry tested. They said flow cytometry often missed small tumor cell populations overlapped by normal cells.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Diagnostic accuracy study comparing DNA flow cytometry with DNA image cytometry on the same effusion specimens, with results checked against patient follow-up
• Who was studied: 200 effusions of the serous cavities: 142 pleural, 48 peritoneal, 6 pericardial and 4 cul-de-sac specimens. By cytology, 80 were tumor cell-positive, 74 negative and 46 equivocal. They were examined routinely between April and October 1998 at the Institute of Cytopathology, Heinrich-Heine-University, Düsseldorf. Follow-up identified 9 malignant mesotheliomas among them.
• Exposure: No asbestos or other exposure was studied. The study compared two methods of measuring DNA content in effusion cells: DNA flow cytometry with DAPI-SR staining, and DNA image cytometry with Feulgen staining.
• Main results:
  • In benign (tumor cell-negative) effusions, neither method showed DNA-aneuploidy. This corresponds to a specificity of 100.0% for both methods.
  • Of the 80 tumor cell-positive effusions, 47/80 (58.8%) were DNA-aneuploid by flow cytometry and 70/80 (87.5%) by image cytometry.
  • Among the 80 tumor cell-positive effusions there were six mesotheliomas. Three were DNA-aneuploid by flow cytometry and four by image cytometry.
  • In the 46 cytologically equivocal effusions, sensitivity for malignancy was 32.1% (9/28) by flow cytometry and 75.0% (21/28) by image cytometry, among those found to be malignant. Specificity was 100.0% (18/18) for both methods, among those found to be benign.
  • In the equivocal effusions, the positive predictive value of DNA-aneuploidy was 100.0% for both methods.
  • In the equivocal effusions, the negative predictive value was 48.6% (18 of 37) for flow cytometry and 72.0% (18 of 25) for image cytometry.
  • Three of the equivocal effusions were due to malignant mesotheliomas. DNA-aneuploidy was detected in two of these by each method.
  • Across all 200 effusions, total sensitivity was 51.9% for flow cytometry and 84.3% for image cytometry. Total specificity was 100.0% for both, and total diagnostic accuracy was 74.0% and 91.5%, respectively.
  • In 40 tumor cell-containing effusions (26 cytologically positive, 14 equivocal), image cytometry detected aneuploidy while flow cytometry did not.
• The authors' conclusion: The authors concluded that, in searching for DNA-aneuploidy as a marker of tumor cells in serous effusions, image cytometry showed higher sensitivity than monoparametric (single-parameter) flow cytometry.
• Limitations the authors state:
  • The authors said flow cytometry missed aneuploidy mainly because small tumor cell populations were overlapped by large numbers of normal cells.
  • In some of the cases missed by flow cytometry, too few cells could be measured and measurement variation was too high. The authors said this reflects routine effusion material.
  • The authors noted that image cytometry measures only a limited number of cells and is relatively time consuming.

Topics

Medical terms in this study, explained in our Lexicon: Cytology.

Related studies

• Immunocytochemistry and DNA-image cytometry in diagnostic effusion cytology I. Prevalence of markers in tumour cell positive and negative smears — H. Motherby, M. Kube, et al. (1999)
• Additional techniques in serous effusions — A.G. Hanselaar (2002)
• Robust Cell Detection and Segmentation for Image Cytometry Reveal Th17 Cell Heterogeneity — T. Tsujikawa, G. Thibault, et al. (2019)
• The diagnostic utility of D2-40, calretinin, CK5/6, desmin and MOC-31 in the differentiation of mesothelioma from adenocarcinoma in pleural effusion cytology — T.S. Hyun, M. Barnes, et al. (2012)
• The diagnostic role of BAP1 in serous effusions — B. Davidson, M. Tötsch, et al. (2018)
• Flow cytometric analysis of ploidy in immunohistochemically confirmed examples of malignant epithelial mesothelioma — H.F. Frierson, S.E. Mills, et al. (1988)

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