Adenomatoid tumours: an immunohistochemical and ultrastructural appraisal of their histogenesis

Our plain-English summary of Adenomatoid tumours: an immunohistochemical and ultrastructural appraisal of their histogenesis, by T.J. Stephenson, P.M. Mills (The Journal of Pathology, 1986).

The study

• Authors: T.J. Stephenson, P.M. Mills
• Journal: The Journal of Pathology
• Published: 1986;148(4):327-35
• Cited by: 49 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The histogenesis of adenomatoid tumour has continued to provoke debate since Golden and Ash suggested the term in 1945 for a characteristic benign neoplasm typically found in the uterus, fallopian tube or epididymis. Endothelial, epithelial, mesonephric, müllerian and mesothelial histogenesis have been suggested. The balance of evidence suggests mesothelial derivation, but two recent studies point to endothelial origin for at least some of these tumours. Twenty-two histologically typical adenomatoid tumours were studied by electron microscopy, mucin histochemistry and immunohistochemistry. Ultrastructurally, all cases showed vacuolated cells bearing long bushy microvilli and the features were not those of endothelial cells. Glandular spaces contained acid mucopolysaccharide consistent with hyaluronic acid. Immunohistochemical double labelling techniques showed the cells lining such spaces to contain cytokeratin in the absence of factor VIII related antigen and receptors for Ulex europaeus I lectin which were expressed in the endothelium of tumour blood vessels. The evidence points to mesothelial histogenesis in all cases examined.

In plain English

This laboratory study from the Department of Pathology, University of Sheffield, examined adenomatoid tumours, a benign tumour of the genital tract, to work out which cell type they arise from. Tissue from 22 tumours was studied. The tumours came from the uterus, fallopian tube, epididymis, spermatic cord and one male hernial sac. Under the electron microscope, tumour cells in all cases had long bushy microvilli (fine surface projections) like those of control mesothelial cells, the cells that line body cavities. They lacked features of blood-vessel lining cells. In all cases the tumour spaces contained a mucus-like substance consistent with hyaluronic acid. Tumour cells contained cytokeratin, a mesothelial marker, and did not carry the blood-vessel markers, which did stain small vessels inside the tumours. The authors concluded that the evidence points to a mesothelial origin in all cases examined. They noted that cytokeratin does not rule out origin from specialised Müllerian epithelium. The article does not discuss asbestos.

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 of archived tumour tissue using electron microscopy, mucin histochemistry and immunohistochemistry
• Who was studied: 22 adenomatoid tumours from paraffin blocks, Department of Pathology, University of Sheffield, U.K. According to the case table: 9 from the uterus, 6 from the epididymis, 4 from the spermatic cord, 2 from the fallopian tube and 1 from a male hernial sac, 1 to 4 cm in diameter. Control mesothelium came from hernia sacs and peritoneum over removed uteri; control blood-vessel lining came from surgical margins. Dates of the cases are not given.
• Exposure: None. The study examined tumour tissue and did not study asbestos or any other exposure.
• Main results:
  • In all 22 cases, electron microscopy showed long bushy microvilli on cells lining the tumour spaces and on isolated cells in the stroma. These were similar to control mesothelium. Unlike control blood-vessel lining, the tumour cells showed no multi-layered basal lamina or pinocytotic activity.
  • In all cases, alcian blue staining showed acid mucopolysaccharide in the tumour spaces. The staining disappeared after digestion with hyaluronidase, consistent with hyaluronic acid.
  • In all cases, control mesothelium, the flattened tumour cells lining the spaces and the cuboidal tumour cells in the stroma contained cytokeratin.
  • Control blood-vessel lining did not stain for cytokeratin but did stain for factor VIII-related antigen and UEA-I lectin. Both of these blood-vessel markers showed numerous small vessels within the tumours.
  • Five highly vascular cases (cases 2, 4, 9, 16 and 18) were double-stained. Blood-vessel cells stained brown and tumour cells stained blue, with no overlap.
  • Cytokeratin was present and blood-vessel markers were absent in tumour cells in all cases, whatever the dominant microscopic pattern of the tumour.
• The authors' conclusion: The authors concluded that the evidence points to a mesothelial origin in all the adenomatoid tumours they examined. They suggested that earlier studies reporting blood-vessel-cell features may have suffered from misdiagnosis or sampling errors.
• Limitations the authors state:
  • Electron microscopy could only be done on tissue retrieved from paraffin blocks. The authors judged preservation adequate.
  • The cytokeratin finding, while consistent with mesothelial cells, does not exclude origin from specialised epithelium possibly of Müllerian origin.

Topics

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

Medical terms in this study, explained in our Lexicon: Adenomatoid Tumor, Neoplasm, Epididymis, Immunohistochemistry, Hyaluronic Acid.

Related studies

• Immunohistochemical evidence of the mesothelial histogenesis of a uterine adenomatoid tumor — Y. Satoh, M. Hiraguchi, et al. (1998)
• Adenomatoid tumour of the epididymis: histochemical and ultrastructural study of 2 cases — M. Nistal, F. Contreras, et al. (1978)
• Adenomatoid tumours: a mucin histochemical and immunohistochemical study — M.J. Goddard, J.W. Grant (1992)
• Solitary fibrous tumour of the pleura: an ultrastructural and immunohistochemical study — S. Keating, G.T. Simon, et al. (1987)
• TRAF7 mutations and immunohistochemical study of uterine adenomatoid tumor compared with malignant mesothelioma — H. Itami, T. Fujii, et al. (2021)
• Uterine adenomatoid tumors confirmed by immunohistochemical staining — M. Irikoma, K. Takahashi, et al. (2001)

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