Histological comparison of malignant epithelioid mesothelioma in young and adult cattle

Our plain-English summary of Histological comparison of malignant epithelioid mesothelioma in young and adult cattle, by Y. Kawashima, A. Fujimoto, M. Saito, et al (The Journal of Veterinary Medical Science, 2021).

The study

• Authors: Y. Kawashima, A. Fujimoto, M. Saito, O. Mikami, Y. Ishikawa, K. Kadota
• Journal: The Journal of Veterinary Medical Science
• Published: 2021;83(6):968-972
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

The histology and immunohistochemistry of pleomorphic and conventional epithelioid mesotheliomas were examined. The former was detected in two young calves aged 2 and 4 months and was characterized by pleomorphic and atypical cells with decreased expression of cytokeratin 7 (CK7). In contrast, the latter was found in a 31-month-old heifer, consisting of tumor cells uniform in size and shape with CK7 expression in nearly all cells. Production of collagen by tumor cells was demonstrated in both histological types, and was considered to be characteristic of bovine epithelioid mesothelioma. Pleomorphic mesothelioma is far more pleomorphic and mitotically active than conventional mesothelioma, and its normal counterpart may be immature mesothelial cells with high proliferation potential, which exist in fetal life and early calfhood.

In plain English

This short veterinary report described mesothelioma, a cancer of the lining of body cavities, in three cattle. Two were young Holstein calves, a 2-month-old male and a 4-month-old female, with tumors mainly on the lining of the abdomen (peritoneum). The third was a 31-month-old crossbred heifer that appeared healthy before slaughter and had tumors on the lining of the chest (pleura). The authors examined tumor tissue under the microscope with special stains. In both calves the tumor cells were abnormal and varied in size and shape, and the authors diagnosed pleomorphic mesothelioma. A marker called cytokeratin 7 was found mainly in better-differentiated cells and rarely in the pleomorphic cells. In the heifer, tumor cells were relatively uniform, and most were positive for the cytokeratin markers tested. Tumor cells in the cases produced collagen, which the authors considered helpful for diagnosis in cattle. The article did not study asbestos or any other exposure in these animals. It mentioned asbestos only when describing earlier human research. The authors suggested that pleomorphic mesothelioma may arise differently in humans and calves.

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: veterinary case series (short pathology note) of three cattle with mesothelioma, examined by histology and immunohistochemistry
• Who was studied: Three cattle: a 2-month-old Holstein male calf (case 1), a 4-month-old Holstein female calf (case 2), and a 31-month-old crossbred (Japanese Black x Holstein) heifer that appeared healthy before slaughter (case 3); dates and farm locations not stated
• Exposure: No exposure was studied in these cattle. Asbestos is mentioned only when describing human pleomorphic mesothelioma from earlier research.
• Main results:
  • Case 1 (2-month-old calf): tumor nodules up to 1 cm were spread over the ruminal serosa, splenic capsule and parietal peritoneum
  • Case 2 (4-month-old calf): nodules up to 5 cm were scattered over the peritoneum, with a few on the pulmonary and pericardial pleura
  • Case 3 (31-month-old heifer): tumor nodules or masses were on the costal pleura
  • Tumor cells in the two calves (cases 1 and 2) showed pleomorphism and atypia
  • In the heifer (case 3), tumor cells were relatively uniform in size and shape
  • In case 1, cytokeratin 7 was expressed chiefly in well-differentiated cuboidal cells
  • In case 2, pleomorphic cells expressing cytokeratin 7 were rare
  • In case 3, most tumor cells were positive for the cytokeratin markers examined and for the proliferation markers PCNA and Ki-67
  • The calf and heifer tumors were characterized by collagen production by tumor cells. The authors considered this helpful for telling these tumors apart from other cancers in cattle.
  • Cytokeratin 20 was expressed in all three cases
  • No metastasis was observed in the heifer (case 3)
• The authors' conclusion: The authors suggested, as an inference from their observations and earlier reports, that the pathogenesis (how the disease develops) of pleomorphic mesothelioma may differ between humans and calves. They also proposed that the calf tumors may arise from immature mesothelial cells with high growth potential. They did not investigate the cause in these animals.
• Limitations the authors state:
  • In case 2, no tissues were collected for histology at necropsy because of postmortem changes. Histology relied on nodules removed earlier during surgery.

Topics

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

Medical terms in this study, explained in our Lexicon: Epithelioid, Mesothelioma, Histology, Immunohistochemistry, Pleomorphic, Collagen, Mesothelial Cells.

Related studies

• Congenital tumours and tumour-like lesions in domestic animals. 1. Cattle. A review — W. Misdorp (2002)
• Tumours in calves: comparative aspects — W. Misdorp (2002)
• 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)
• Expression of thrombomodulin, calretinin, cytokeratin 5/6, D2-40 and WT-1 in a series of primary carcinomas of the lung: an immunohistochemical study in comparison with epithelioid pleural mesothelioma — C.E. Comin, L. Novelli, et al. (2014)
• A Subset of Malignant Mesotheliomas in Young Adults Are Associated With Recurrent EWSR1/FUS-ATF1 Fusions — P. Desmeules, P. Joubert, et al. (2017)
• Malignant epithelioid mesothelioma: anti-mesothelial marker expression correlates with histological pattern — R.L. Attanoos, R. Webb, et al. (2001)

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