Flow cytometric analysis of ploidy in immunohistochemically confirmed examples of malignant epithelial mesothelioma

Our plain-English summary of Flow cytometric analysis of ploidy in immunohistochemically confirmed examples of malignant epithelial mesothelioma, by H.F. Frierson, S.E. Mills, J.F. Legier (American Journal of Clinical Pathology, 1988).

The study

• Authors: H.F. Frierson, S.E. Mills, J.F. Legier
• Journal: American Journal of Clinical Pathology
• Published: 1988;90(3):240-3
• Cited by: 34 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Flow cytometry was used to compare the DNA content of 28 fresh effusion specimens that contained abundant proliferating mesothelial cells, with the ploidy profiles for 19 formalin-fixed, paraffin-embedded examples of malignant epithelial mesothelioma. Each mesothelioma lacked staining with periodic acid-Schiff (PAS) after diastase pretreatment. Nineteen of 19 mesotheliomas were immunoreactive for cytokeratin, 13 of 19 for epithelial membrane antigen, 0 of 19 for Leu-M1, and 0 of 19 for carcinoembryonic antigen. Each benign fluid specimen was DNA diploid. Nine of the deparaffinized mesotheliomas were DNA diploid, and seven had additional G0G1 peaks signifying DNA aneuploidy. Histograms from the remaining three mesotheliomas showed G0G1 peaks with prominent shoulders, probably indicating low-degree hyperdiploidy. The results suggest that ploidy analysis by flow cytometry might be useful for the separation of mesothelioma from proliferating mesothelial cells in effusion specimens. Although only 53% of the mesotheliomas were DNA aneuploid, the finding of DNA aneuploidy in an effusion specimen that contains atypical mesothelial cells would strongly support a diagnosis of mesothelioma.

In plain English

This laboratory study, from the University of Virginia Medical Center and Riverside Hospital in Virginia, used flow cytometry, a method that measures how much DNA cells contain. The aim was to see whether it could help tell malignant epithelial mesothelioma apart from benign, multiplying mesothelial cells in body-cavity fluid. The authors tested 28 fluid samples (6 peritoneal and 22 pleural) that contained many benign mesothelial cells. They also tested stored, paraffin-embedded tissue from 19 mesotheliomas confirmed with special stains. The article did not report asbestos exposure. All 28 benign samples had a normal (diploid) DNA pattern. Ten of the 19 mesotheliomas had abnormal (aneuploid) DNA content. Seven showed a distinct extra DNA peak, with a DNA index from 1.17 to 1.87. Three showed a shoulder on the peak that the authors read as probably a slight DNA excess. Nine (47%) were diploid. The authors concluded that aneuploidy in fluid containing atypical mesothelial cells would strongly support a diagnosis of mesothelioma, but a diploid result does not exclude it. They noted that small abnormal peaks might be missed in stored tissue. The mesotheliomas were tested as tissue, not as fluid samples.

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: Laboratory flow cytometry study comparing the DNA content of benign effusion specimens with that of archived malignant epithelial mesothelioma tissue
• Who was studied: 28 effusion specimens (6 peritoneal, 22 pleural) containing abundant benign, proliferating mesothelial cells, plus formalin-fixed, paraffin-embedded tissue from 19 malignant epithelial mesotheliomas obtained by open biopsy or at autopsy. The authors were at the University of Virginia Medical Center, Charlottesville, and Riverside Hospital, Newport News, Virginia. Study dates were not given.
• Exposure: Not studied; the article does not report asbestos or any other exposure for the patients.
• Main results:
  • All 28 benign effusion specimens were DNA diploid, with no additional G0-G1 peaks.
  • 10 of the 19 mesotheliomas were DNA aneuploid.
  • In 7 of the aneuploid mesotheliomas, which had discrete additional G0-G1 peaks, the DNA index ranged from 1.17 to 1.87 (median 1.50).
  • The other 3 aneuploid mesotheliomas showed a prominent shoulder to the right of a G0-G1 peak, which the authors said probably indicated low-degree hyperdiploidy.
  • 9 of 19 mesotheliomas (47%) were DNA diploid.
  • No mesothelioma showed multiple aneuploid peaks (multiploidy).
  • All 19 mesotheliomas were strongly immunoreactive for cytokeratin, 13 stained for epithelial membrane antigen, and all were negative for CEA and Leu-M1.
• The authors' conclusion: The authors concluded that DNA aneuploidy in an effusion specimen containing atypical, proliferating mesothelial cells would be strong evidence supporting a diagnosis of malignant epithelial mesothelioma. They added that finding only diploid cells does not exclude mesothelioma.
• Limitations the authors state:
  • Small aneuploid or near-diploid peaks might not have been detectable in histograms from archival, formalin-fixed, paraffin-embedded material, which shows more debris and broader peaks than fresh tissue.
  • More mesotheliomas would need to be examined to judge whether multiploidy helps separate mesothelioma from pulmonary adenocarcinoma.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Mesothelial Cells, Epithelial Membrane Antigen (EMA), Carcinoembryonic Antigen (CEA).

Related studies

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• Interphase cytogenetics on paraffin sections of malignant pleural mesothelioma. A comparison to conventional karyotyping and flow cytometric studies — M. Tiainen, A. Hopman, et al. (1992)
• Prognostic significance of flow cytometric DNA analysis in patients with malignant pleural mesothelioma — S. Emri, H. Akbulut, et al. (2001)
• DNA analysis by flow cytometry in malignant pleural mesothelioma: relationship to histology and survival — H. Dazzi, N. Thatcher, et al. (1990)
• Flow cytometric analysis of a localized malignant mesothelioma — J.J. Gómez-Román, R. Mons-Lera, et al. (2002)

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