Hyaluronate binding probe and CD44 in the differential diagnosis of malignant effusions: disappointing results in cytology material

Our plain-English summary of Hyaluronate binding probe and CD44 in the differential diagnosis of malignant effusions: disappointing results in cytology material, by A.C. Filie, A. Abati, P. Fetsch, et al (Diagnostic Cytopathology, 1998).

The study

• Authors: A.C. Filie, A. Abati, P. Fetsch, N. Azumi
• Journal: Diagnostic Cytopathology
• Published: 1998;18(6):473-4
• Type of article: Letter
• Cited by: 19 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

In this letter, the authors examined whether a biotinylated hyaluronate binding probe and an antibody to CD44, the cell surface receptor for hyaluronan, could help distinguish malignant mesothelioma from metastatic adenocarcinoma in cytology material from malignant effusions. An earlier study had found the probe highly predictive of mesothelioma in surgical pathology material. Cell block preparations from 21 mesotheliomas, 22 metastatic adenocarcinomas, 1 case of reactive mesothelial cells and 1 mesothelioma cell line were retrieved from the files of the Cytopathology Section, National Cancer Institute (Bethesda, Maryland). Sections were stained with the probe and for CD44, and three observers reviewed them without knowing the final diagnosis. Two cases were not scored because of absent or scanty tumor cells. The probe stained 19 of 20 mesotheliomas (95%) and 19 of 21 adenocarcinomas (90.5%). CD44 showed membranous staining in 18 of 20 mesotheliomas (90%) and 9 of 21 adenocarcinomas (43%). The reactive mesothelial cells stained focally for CD44. The authors suggested that hyaluronic acid in the effusion fluid may stick to or be taken up by floating adenocarcinoma cells. They concluded that neither the probe nor CD44 was useful for this distinction in effusion cell blocks, although the probe appeared to work well in surgical tissue sections. They stated that the small number of benign samples did not allow conclusions about separating benign from malignant mesothelial cells.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

In this letter to the editor, the authors tested two laboratory stains for telling malignant mesothelioma apart from metastatic adenocarcinoma (cancer spread from elsewhere) in fluid samples. They used cell blocks from 21 mesothelioma cases, 22 metastatic adenocarcinoma cases, one reactive (non-cancerous) mesothelial case and one mesothelioma cell line from National Cancer Institute files. Three observers read the slides without knowing the diagnosis, and two cases could not be scored. A hyaluronate binding probe stained 19 of 20 mesotheliomas (95%) but also 19 of 21 adenocarcinomas (90.5%). CD44 staining appeared in 18 of 20 mesotheliomas (90%) and 9 of 21 adenocarcinomas (43%). The authors concluded that the probe, which they said appears to work very well in surgical tissue, was not useful in these effusion cell blocks. They also concluded that CD44 was not useful for telling the two cancers apart in this material. They suggested that hyaluronic acid in the fluid might stick to floating adenocarcinoma cells. They noted too few benign samples to judge CD44 for separating benign from malignant mesothelial cells. Asbestos exposure was not studied.

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: Small diagnostic comparison of two stains on cytology cell blocks, reported as a letter to the editor; slides were read by three observers who did not know the final diagnosis
• Who was studied: Cell block preparations from effusion (fluid) specimens: 21 cases of mesothelioma, 22 cases of metastatic adenocarcinoma, 1 case of reactive mesothelial cells and 1 mesothelioma cell line, from the Cytopathology Section files of the National Cancer Institute, Bethesda, MD. The site of the mesotheliomas (pleural or peritoneal) is not stated.
• Exposure: No asbestos exposure was studied. The study tested two laboratory stains: a hyaluronate binding probe and immunohistochemistry for CD44.
• Main results:
  • Two cases were not scored because no tumor cells, or too few, were on the slides. The results therefore cover 20 mesotheliomas and 21 adenocarcinomas.
  • Mesothelioma cases: 19 of 20 (95%) stained positive with the hyaluronate probe.
  • Metastatic adenocarcinoma cases: 19 of 21 (90.5%) also stained positive with the hyaluronate probe.
  • Strong background staining was seen in 40% of mesotheliomas and 9.5% of adenocarcinomas.
  • CD44 membranous staining was seen in 18 of 20 mesotheliomas (90%) and in 9 of 21 metastatic adenocarcinomas (43%).
  • The single case of reactive mesothelial cells stained focally positive for CD44.
  • The authors offered a possible explanation for the positive adenocarcinoma results: hyaluronic acid in the fluid may stick to, or be taken into, the floating cancer cells.
• The authors' conclusion: The authors concluded that the hyaluronate probe appears to work very well in tissue sections from surgical pathology material, where it should be used as an adjunctive diagnostic tool, but that the same is not true for cell block sections from malignant effusions. They also concluded that CD44 antibody is not useful for telling metastatic adenocarcinoma from mesothelioma in cytologic material.
• Limitations the authors state:
  • Only one benign (reactive) mesothelial sample was studied. The authors could not say whether CD44 helps separate benign from malignant mesothelial cells.

Topics

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

Medical terms in this study, explained in our Lexicon: Differential Diagnosis, Cytology, Malignant Mesothelioma, Adenocarcinoma, Mesothelioma, Pathology, Cell Block, Reactive Mesothelial Cells.

Related studies

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• Utility of hyaluronic acid in pleural fluid for differential diagnosis of pleural effusions: likelihood ratios for malignant mesothelioma — S. Atagi, M. Ogawara, et al. (1997)
• Synergistic Enhancement of Cellular Uptake With CD44-Expressing Malignant Pleural Mesothelioma by Combining Cationic Liposome and Hyaluronic Acid-Lipid Conjugate — Y. Sakurai, A. Kato, et al. (2019)
• Cytological differential diagnosis among adenocarcinoma, epithelial mesothelioma, and reactive mesothelial cells in serous effusions by immunocytochemistry — X.Y. Su, G.D. Li, et al. (2011)
• Small orangiophilic squamous-like cells: an underrecognized and useful morphological feature for the diagnosis of malignant mesothelioma in pleural effusion cytology — L. Chen, S.G. Caldero, et al. (2014)
• The value of anti-calretinin antibody in the differential diagnosis of normal and reactive mesothelia versus metastatic tumors in effusion cytology — H. Nagel, B. Hemmerlein, et al. (1998)

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