Immunohistochemical staining for vimentin and keratin in malignant mesothelioma

Our plain-English summary of Immunohistochemical staining for vimentin and keratin in malignant mesothelioma, by A. Churg (The American Journal of Surgical Pathology, 1985).

The study

• Author: A. Churg
• Journal: The American Journal of Surgical Pathology
• Published: 1985;9(5):360-5
• Cited by: 130 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Because tissue culture studies have suggested that mesothelial cells might produce large amounts of vimentin, I stained eight mesotheliomas (two fixed in alcohol) for vimentin using the Gown and Vogel monoclonal antibody 43 beta E8. The two tumors that had alcohol fixed blocks were strongly positive for vimentin, whereas one of the tumors fixed only in formalin showed moderately strong staining and two others showed very weak focal positivity; the remaining tumors were negative. In the mesotheliomas that did stain, both epithelial and spindled elements gave a positive reaction. Three alcohol-fixed lung cancers and two blocks of alcohol-fixed pleura failed to stain for vimentin. By contrast, all mesotheliomas and carcinomas, whether alcohol or formalin fixed, as well as sections of pleura, were strongly positive when stained with anticytokeratin antibody 35 beta H11. I conclude that the combination of staining for vimentin and keratin might be a useful diagnostic finding in malignant mesothelioma, but that specially fixed material is required for reliable vimentin staining.

In plain English

This laboratory study tested whether mesothelioma tissue stains for vimentin, a protein that cell-culture studies had suggested mesothelial cells make in large amounts. The author stained tissue from eight pleural mesotheliomas, three lung adenocarcinomas and normal pleura from two autopsies for vimentin and for a cytokeratin. All eight mesotheliomas stained strongly for cytokeratin. Vimentin staining was strong only in the two tumors that had alcohol-fixed tissue, and the formalin-fixed tissue of those two tumors was negative. Among tumors fixed only in formalin, one stained moderately, two stained very weakly, and the rest were negative. The three lung cancers and the normal pleura stained for cytokeratin but not for vimentin. A note added in proof reported 27 further mesotheliomas: three of three alcohol-fixed and nine of 24 formalin-fixed cases were vimentin-positive. The author concluded that combined vimentin and keratin staining might be useful in diagnosing malignant mesothelioma, if confirmed in more cases, but that specially fixed tissue is needed for reliable vimentin staining. 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: Laboratory immunohistochemical (tissue-staining) study of a small series of tumor and normal tissue specimens
• Who was studied: Eight pleural mesotheliomas (two autopsy and six surgical specimens; five purely epithelial, three mixed epithelial and sarcomatous), three lung adenocarcinomas, and parietal pleura from two autopsies, studied at the Department of Pathology, University of British Columbia, Vancouver. No study dates are given.
• Exposure: No asbestos exposure was studied. The 'exposure' was laboratory staining with a monoclonal antivimentin antibody (43βE8) and a monoclonal anticytokeratin antibody (35βH11), on tissue fixed in formalin or in absolute alcohol.
• Main results:
  • All eight mesotheliomas stained strongly and diffusely for cytokeratin. Staining was somewhat stronger in alcohol-fixed than in formalin-fixed material.
  • In mesotheliomas, strong vimentin staining was seen only in the two alcohol-fixed tumors. The formalin-fixed blocks of those same two tumors were negative.
  • Among formalin-fixed mesotheliomas, one showed moderate vimentin staining, two showed very weak and focal staining, and the remaining cases were negative.
  • In mesotheliomas that stained for vimentin, staining appeared in both epithelial and spindle elements, but in many fewer cells than keratin staining.
  • The three lung carcinomas stained strongly for keratin in both alcohol- and formalin-fixed tissue. Their vimentin staining was consistently negative.
  • In normal pleura, mesothelial cells stained strongly for keratin but did not stain for vimentin.
  • In formalin-fixed cases with no vimentin staining, the internal control cells also failed to stain. The author took this to show considerable variation in how well vimentin is preserved.
  • Note added in proof: in 27 additional mesotheliomas, alcohol-fixed cases were three of three vimentin-positive, formalin-fixed cases were nine of 24 positive, and all were strongly positive for cytokeratin.
• The authors' conclusion: The author concluded that the combination of vimentin and keratin staining might be a useful diagnostic finding in malignant mesothelioma, but that specially fixed (alcohol-fixed) material is required for reliable vimentin staining.
• Limitations the authors state:
  • The author stated that the diagnostic value of the staining combination depends on confirmation in larger numbers of cases.
  • Renal cell carcinomas and synovial sarcomas also produce both keratin and vimentin. The author described them as a possible, though clinically improbable, source of confusion with this staining scheme.
  • The author considered whether the vimentin staining could be a cross-reaction with keratins. The author relied on the antibody's developers, who found no cross-reactivity with keratins but some with gliofibrillary acidic protein.
  • Vimentin is generally not thought to survive formalin fixation, and its preservation varied considerably among cases.
  • Why mesotheliomas stained for vimentin while non-neoplastic mesothelial cells did not was uncertain. Reactive (proliferating) mesothelium was not tested.

Topics

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

Medical terms in this study, explained in our Lexicon: Immunohistochemistry, Malignant Mesothelioma, Mesothelial Cells, Mesothelioma, Monoclonal Antibody, Lung Cancer, Pleura, Carcinoma.

Related studies

• The distribution of vimentin and keratin in epithelial and nonepithelial neoplasms. A comprehensive immunohistochemical study on formalin- and alcohol-fixed tumors — N. Azumi, H. Battifora (1987)
• Distinct keratin patterns demonstrated by immunoperoxidase staining of adenocarcinomas, carcinoids, and mesotheliomas using polyclonal and monoclonal anti-keratin antibodies — H.J. Kahn, P.S. Thorner, et al. (1986)
• Expression of calretinin, thrombomodulin, keratin 5, and mesothelin in lung carcinomas of different types: an immunohistochemical analysis of 596 tumors in comparison with epithelioid mesotheliomas of the pleura — M. Miettinen, M. Sarlomo-Rikala (2003)
• Keratin protein immunoreactivity of sarcomatoid and mixed types of diffuse malignant mesothelioma: an immunoperoxidase study of 30 cases — A.G. Montag, G.S. Pinkus, et al. (1988)
• The applicability of a keratin 7 monoclonal antibody in routinely Papanicolaou-stained cytologic specimens for the differential diagnosis of carcinomas — J.H. Baars, J.L. De Ruijter, et al. (1994)
• Unusual primary lung neoplasms: spindle cell and undifferentiated lung carcinomas expressing only vimentin — S.P. Hammar, K.O. Hallman (1990)

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