Distinct keratin patterns demonstrated by immunoperoxidase staining of adenocarcinomas, carcinoids, and mesotheliomas using polyclonal and monoclonal anti-keratin antibodies

Our plain-English summary of Distinct keratin patterns demonstrated by immunoperoxidase staining of adenocarcinomas, carcinoids, and mesotheliomas using polyclonal and monoclonal anti-keratin antibodies, by H.J. Kahn, P.S. Thorner, H. Yeger, et al (American Journal of Clinical Pathology, 1986).

The study

• Authors: H.J. Kahn, P.S. Thorner, H. Yeger, D. Bailey, R. Baumal
• Journal: American Journal of Clinical Pathology
• Published: 1986;86(5):566-74
• Cited by: 42 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The authors assessed whether distinct patterns for keratin could be demonstrated in 10 adenocarcinomas, 10 carcinoids, and 4 mesotheliomas by an immunoperoxidase reaction using 3 polyclonal and 3 monoclonal antibodies to keratin. When color development in diaminobenzidine (DAB) was allowed to proceed for less than 2 minutes, distinct patterns for keratin could be demonstrated using two polyclonal and two monoclonal antibodies; these were plasma membrane and/or web-like in the adenocarcinomas, punctate or crescentic in the carcinoids, and perinuclear in the mesotheliomas consisting of tumor cells with abundant cytoplasm. Immunoelectron microscopy using protein A colloidal gold confirmed these results. When color development in DAB was allowed to proceed for more than 2 minutes, only diffuse staining was seen. The distinct patterns of immunostaining for keratin obtained with the shorter color development were helpful in differentiating adenocarcinomas, carcinoids, and mesotheliomas.

In plain English

This was a laboratory study of tumor tissue, not a study of asbestos exposure. The authors, working in Toronto, stained stored tissue samples from 10 adenocarcinomas (ovary, breast and colon), 10 carcinoids (lung, ovary and small bowel) and 4 mesotheliomas. They used three polyclonal and three monoclonal antibodies to keratin, a protein found in epithelial and mesothelial cells. The article does not say where in the body the mesotheliomas arose and gives no exposure history. When the color-developing step (DAB) lasted less than 2 minutes, four of the antibodies showed distinct patterns. These were plasma membrane and/or web-like in adenocarcinomas, a dot or crescent in carcinoids, and around the nucleus (perinuclear) in the two mesotheliomas made of polygonal cells with abundant cytoplasm. The two mesotheliomas made of spindle-shaped cells stained positively but showed no pattern. Color development longer than 2 minutes gave only diffuse staining. Electron microscopy confirmed the patterns. The authors concluded that these patterns may help surgical pathologists tell the three tumor types apart.

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 immunohistochemistry study of archived tumor tissue (immunoperoxidase staining, with immunoelectron microscopy on selected tumors)
• Who was studied: Paraffin tissue blocks from 24 tumors: 10 adenocarcinomas (ovary, breast, colon), 10 carcinoids (lung, ovary, small bowel) and 4 mesotheliomas (site not stated), from the surgical pathology files of Women's College Hospital and Toronto General Hospital, Toronto. No dates or patient details given.
• Exposure: No asbestos or other exposure was studied. The study tested six anti-keratin antibodies (polyclonal: anti-epidermal, anti-Mallory body, wide-spectrum; monoclonal: PKK1, anti-cytokeratin, AE1) and different color-development times in DAB.
• Main results:
  • With DAB color development of less than 2 minutes, distinct keratin patterns were shown using two polyclonal antibodies (anti-epidermal and anti-Mallory body) and two monoclonal antibodies (anti-cytokeratin and AE1)
  • Adenocarcinomas showed a plasma membrane and/or web-like pattern
  • Carcinoids showed a punctate dot or crescent
  • Two of the four mesotheliomas, made of spindle-shaped cells with scanty cytoplasm, stained positively but showed no pattern
  • The other two mesotheliomas, made of polygonal cells with abundant cytoplasm, showed a perinuclear pattern with focal juxtanuclear accentuation
  • With DAB color development longer than 2 minutes, staining was diffuse throughout the cytoplasm of the tumor cells
  • The polyclonal anti-epidermal antibody did not stain the carcinoids, and the wide-spectrum antibody did not stain the adenocarcinomas or carcinoids
  • Immunoelectron microscopy of one adenocarcinoma, one carcinoid and one mesothelioma confirmed the staining patterns
  • In one poorly differentiated colon tumor, the punctate dot pattern pointed to a diagnosis of carcinoid, which electron microscopy confirmed
• The authors' conclusion: The authors concluded that the different keratin patterns may help surgical pathologists distinguish adenocarcinomas, carcinoids and mesotheliomas from each other
• Limitations the authors state:
  • Tissue preservation for immunoelectron microscopy was suboptimal because the tissues had been fixed in formalin

Topics

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

Medical terms in this study, explained in our Lexicon: Adenocarcinoma, Mesothelioma, Monoclonal.

Related studies

• Immunocytological staining reactions of anti-carcinoembryonic antigen, Ca, and anti-human milk fat globule monoclonal antibodies on benign and malignant exfoliated mesothelial cells — A.K. Ghosh, E.B. Butler (1987)
• Immunohistological staining of reactive mesothelium, mesothelioma, and lung carcinoma with a panel of monoclonal antibodies — A.K. Ghosh, K.C. Gatter, et al. (1987)
• Distinguishing malignant mesothelioma from pulmonary adenocarcinoma: an immuno-histochemical approach using a panel of monoclonal antibodies — S.E. Tuttle, J.G. Lucas, et al. (1990)
• 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)
• Keratin proteins and carcinoembryonic antigen in lung carcinoma: an immunoperoxidase study of fifty-four cases, with ultrastructural correlations — J.W. Said, G. Nash, et al. (1983)
• Immunohistochemical staining for vimentin and keratin in malignant mesothelioma — A. Churg (1985)

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