Immunoperoxidase localization of secretory component in reactive mesothelium and mesotheliomas

Our plain-English summary of Immunoperoxidase localization of secretory component in reactive mesothelium and mesotheliomas, by C.S. Ernst, J.J. Brooks (The Journal of Histochemistry and Cytochemistry, 1981).

The study

• Authors: C.S. Ernst, J.J. Brooks
• Journal: The Journal of Histochemistry and Cytochemistry
• Published: 1981;29(9):1102-4
• Cited by: 19 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Immunoperoxidase localization of the secretory component (SC) of immunoglobulin (Ig) A was undertaken on paraffin-embedded tissue to investigate its usefulness in differentiating epithelial from mesothelial neoplasms. Epithelial cells, but not mesothelial cells, have been previously reported to contain SC, which may be involved in the intraepithelial transport of secretory IgA. In this study we report, for the first time, focal but unequivocal staining for SC in reactive mesothelium and mesotheliomas (10/16). Reactivity was not associated with any histologic subtype of malignant mesothelioma although staining was usually seen in the "epithelial" type. The significance in terms of possible mesothelial secretory IgA transport is discussed.

In plain English

This brief laboratory report, from the Hospital of the University of Pennsylvania, tested whether staining for secretory component (SC), a part of immunoglobulin A found in many gland-lining cells, could help pathologists tell mesothelioma apart from adenocarcinoma. The authors stained preserved tissue samples, including reactive mesothelium and 16 malignant mesotheliomas (14 pleural, 2 peritoneal). The article does not discuss asbestos or any other exposure. Ten of the 16 mesotheliomas stained for SC: 5 of 9 epithelial, 1 of 2 fibrosarcomatous and 4 of 5 mixed cases. The staining tended to be focal but strong and was usually in epithelial-type cells. Reactive mesothelium also stained. Completely normal mesothelium did not, and the authors suggested this might be because normal mesothelium is extremely flat, with little cytoplasm available for staining, rather than lacking SC. Among carcinomas, 20 of 27 colonic adenocarcinomas stained. The authors concluded that finding SC in 10 of 16 mesotheliomas ruled it out as a diagnostic tool for this purpose. They suggested that mesothelial cells, at least in a reactive state, may help transport immunoglobulin.

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 (immunoperoxidase staining) study of paraffin-embedded tissue samples; brief report
• Who was studied: 16 cases of malignant mesothelioma (9 epithelial, 2 fibrosarcomatous, 5 mixed; 14 pleural, 2 peritoneal; 10 male, 6 female), plus reactive mesothelium, normal tissues and carcinomas, at the Hospital of the University of Pennsylvania, Philadelphia; dates of cases not given
• Main results:
  • 10 of the 16 malignant mesotheliomas showed secretory component
  • By subtype, 5 of 9 epithelial, 1 of 2 fibrosarcomatous and 4 of 5 mixed mesotheliomas were positive. By site, 9 of 14 pleural and 1 of 2 peritoneal mesotheliomas were positive.
  • In the mesotheliomas, staining tended to be focal but strong and was usually in epithelial-type cells. Intracellular staining was also seen in one fibrosarcomatous mesothelioma.
  • Reactive mesothelium showed focal staining, but completely normal mesothelium did not stain
  • Among carcinomas (briefly summarized, to be detailed in another report), 20 of 27 colonic adenocarcinomas stained. Positives in other adenocarcinomas were 5 of 10 breast, 0 of 5 ovary and 4 of 10 lung.
  • Absorbing the antiserum with purified free secretory component eliminated all specific staining
• The authors' conclusion: The authors concluded that finding secretory component in 10 of 16 malignant mesotheliomas ruled it out as a tool for distinguishing epithelial from mesothelial neoplasms. They suggested that mesothelial cells may play a role similar to epithelial cells in transporting immunoglobulin, at least in a reactive state.
• Limitations the authors state:
  • The authors suggested that the lack of staining in normal mesothelium may reflect how flat these cells are, with little cytoplasm available to stain.
  • The authors stated that better characterization of immunoglobulins in pleural fluids is needed to evaluate the possible transport role.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelium, Mesothelioma, Neoplasm, Mesothelial Cells, Histological Subtype, Malignant Mesothelioma.

Related studies

• Secretory component in pulmonary adenocarcinoma and mesothelioma — A. Kondi-Paphitis, B.J. Addis (1986)
• Immunoperoxidase localization of keratin proteins, carcinoembryonic antigen, and factor VIII in adenomatoid tumors: evidence for a mesothelial derivation — J.W. Said, G. Nash, et al. (1982)
• Use of antibodies to carcinoembryonic antigen and human milk fat globule to distinguish carcinoma, mesothelioma, and reactive mesothelium — R.J. Marshall, A. Herbert, et al. (1984)
• Immunohistological staining of reactive mesothelium, mesothelioma, and lung carcinoma with a panel of monoclonal antibodies — A.K. Ghosh, K.C. Gatter, et al. (1987)
• Immunocytochemistry of CD146 is useful to discriminate between malignant pleural mesothelioma and reactive mesothelium — A. Sato, I. Torii, et al. (2010)
• CD44H expression in reactive mesothelium, pleural mesothelioma and pulmonary adenocarcinoma — R.L. Attanoos, R. Webb, et al. (1997)

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