Congenital polycystic tumor of the atrioventricular node (endodermal heterotopia, mesothelioma): a histogenetic appraisal with evidence for its endodermal origin

Our plain-English summary of Congenital polycystic tumor of the atrioventricular node (endodermal heterotopia, mesothelioma): a histogenetic appraisal with evidence for its endodermal origin, by G. Fine, U. Raju (Human Pathology, 1987).

The study

• Authors: G. Fine, U. Raju
• Journal: Human Pathology
• Published: 1987;18(8):791-5
• Cited by: 23 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The small, variously designated, primary atrioventricular node tumor has been considered to be of endothelial, endodermal, or mesothelial origin. To identify its derivation, we studied seven tumors using silver staining and immunocytochemical labeling with a variety of antibodies. Cytoplasmic argyrophil granules but not argentaffin granules were found in isolated cells among the more numerous tubule-lining cells in four tumors. Serotonin and calcitonin were demonstrable in seven and six tumors, respectively, in a similar distribution to that of the argyrophil cells. A positive reaction of different distribution from that of the argyrophil cells was noted in a varying number of tubule-lining cells for carcinoembryonic antigen, epithelial membrane antigen, and blood group antigen in seven, four, and seven tumors, respectively. No activity was noted in the tumor cells for factor VIII-related antigen or a number of peptides. An endodermal rather than mesothelial or epithelial origin for the tumor is substantiated by the presence of neuroendocrine cells in the midst of the more numerous carcinoembryonic-antigen-positive lining cells of the tumor tubules.

In plain English

This laboratory study examined seven examples of a small tumor found in the atrioventricular node, which is part of the heart's electrical conduction system. The tumor has been called several names, including mesothelioma, and its tissue of origin has been disputed. The article does not discuss asbestos. The authors applied silver stains and antibody-based stains to tumor sections. Cells lining the tumor's small tubules stained for carcinoembryonic antigen (CEA) in seven tumors and for blood group antigen in seven. The article's summary reports epithelial membrane antigen in four. A stain for factor VIII-related antigen, a marker of blood-vessel lining cells, was negative in these cells. Scattered single cells with silver-staining granules were found in four tumors. Cells positive for serotonin and calcitonin, in a similar pattern, were found in seven and six tumors respectively. The authors concluded that the lining cells were epithelial, not endothelial, and that the scattered neuroendocrine cells among them supported an endodermal rather than mesothelial origin. They noted that their CEA antibody can cross-react with other tissues, including mesothelial cells, and that judging staining intensity is subjective.

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 pathology study: silver staining and immunocytochemical (immunoperoxidase) staining of tumor tissue sections
• Who was studied: Seven tumors of the atrioventricular node of the heart. The article gives no patient details, such as age, sex, source or dates.
• Exposure: No exposure was studied. The article does not mention asbestos or any fiber; the word 'mesothelioma' appears only as one of the names used for this heart tumor.
• Main results:
  • In the tubule-lining cells, staining was positive for carcinoembryonic antigen in seven tumors, epithelial membrane antigen in four, and blood group antigen in seven (as given in the article's summary).
  • Tests for factor VIII-related antigen, an endothelial marker, were negative in the tubule-lining cells.
  • The authors interpreted the marker results as showing that the tubule-lining cells are epithelial rather than endothelial.
  • The Churukian-Schenk silver stain identified sparsely scattered single cells among the tubule-lining cells in four of the tumors.
  • The Sievier-Munger and Fontana-Masson stains did not show these silver-positive cells in the two tumors in which they were used.
  • Cells positive for serotonin were seen in seven tumors and cells positive for calcitonin in six, in a distribution similar to the silver-staining cells.
  • Staining was negative with antibodies to ACTH, somatostatin, neuron-specific enolase, thyroglobulin, bombesin, gastrin and pancreatic polypeptide.
• The authors' conclusion: The authors concluded that serotonin- and calcitonin-positive cells, distributed like the argyrophil cells among the tubule-lining cells, give additional support for an endodermal origin of the tumor, as opposed to the mesothelial origin that had been proposed.
• Limitations the authors state:
  • The polyclonal CEA antibody used can cross-react with non-endodermal tissues, including mesothelial cells, so CEA cannot be accepted without doubt as an endodermal marker in this tumor.
  • Judging staining intensity is subjective and may be affected by technique, fixation and tissue preservation.
  • Epithelial membrane antigen and keratin staining cannot exclude a mesothelial origin, and keratin was not tested in this study.

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, Tubule, Carcinoembryonic Antigen (CEA), Epithelial Membrane Antigen (EMA).

Related studies

• Mesothelioma of the atrioventricular node and congenital complete heart block — R. Subramanian, B. Flygenring (1989)
• Mesothelioma of the atrioventricular node — K. Nishida, G. Kamijima, et al. (1985)
• "Mesothelioma of the atrioventricular node" with long-standing complete heart block. Report of a case — I.R. Wanless, B.W. Mielke, et al. (1975)
• Corpora amylacea in mesothelioma of the atrioventricular node — R. David, Y. Hiss (1978)
• Primary mesothelioma of atrioventricular node: cause of sudden death — E.H. Hemsted (1986)
• Synovial sarcoma of the heart arising from a so-called mesothelioma of the atrio-ventricular node — E.A. Sheffield, B. Corrin, et al. (1988)

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