Metastatic pleural mesothelioma presenting initially as multiple gastric and colonic polyps

Our plain-English summary of Metastatic pleural mesothelioma presenting initially as multiple gastric and colonic polyps, by A. Alhumidi, A. Alqahtani (Journal of Surgical Case Reports, 2020).

The study

• Authors: A. Alhumidi, A. Alqahtani
• Journal: Journal of Surgical Case Reports
• Published: 2020;2020(7):rjaa203
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

It is extremely rare for malignant mesothelioma to present as gastrointestinal polyps. This case report documents the presentation of malignant mesothelioma in a 72-year-old as rectal bleeding and weight loss. Endoscopically, there were multiple gastric and colonic polyps. Histopathologically, there were atypical cells in the lamina propria with benign surface epithelium. The cells tested positive for cytokeratin, calretinin and D2-40 and negative for CD45, CD117, Ber-EP4 and CEA, confirming the diagnosis of metastatic mesothelioma. A computed tomography scan of the chest showed nodular thickening of the left lower pleura that was compatible with a diagnosis of primary pleural mesothelioma. We conclude that metastatic mesothelioma can sometimes present as gastrointestinal polyps.

Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author(s) 2020.

In plain English

This case report described one patient, a 72-year-old non-smoking man with no previous medical or surgical history, who had had rectal bleeding and weight loss for three months. Endoscopy of the upper digestive tract found three sessile (flat-based) polyps in the stomach. Colonoscopy found sessile polyps in the colon, some of them ulcerated. The removed polyps measured between 0.4 and 0.6 cm. Under the microscope, tumor cells were found in the lamina propria, the tissue layer beneath a largely normal surface lining. The tumor cells stained positive for cytokeratin, calretinin and D2-40. They stained negative for CEA, CD45, CD117, Ber-EP4, cytokeratin 7 and cytokeratin 20. A diagnosis of metastatic mesothelioma was made. A CT scan showed nodular thickening of the left lower pleura, which the authors described as compatible with primary pleural mesothelioma. The patient did not return for scheduled follow-up appointments. The report did not mention asbestos or any other exposure. The authors concluded that metastatic disease is uncommon when malignant mesothelioma is first diagnosed. They also concluded that a full clinical history, imaging and immunohistochemical studies are needed to make the diagnosis.

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: case report (single patient)
• Who was studied: One 72-year-old non-smoking man with no previous medical or surgical history, presenting with a 3-month history of rectal bleeding and weight loss; place and dates of care not stated
• Exposure: Not reported; the article does not mention asbestos or any other exposure
• Main results:
  • Upper endoscopy found three sessile polyps in the body of the stomach; colonoscopy found sessile colonic polyps, some ulcerated
  • The removed polyps measured between 0.4 and 0.6 cm
  • The gastric and colonic polyps showed tumor cells in the lamina propria with normal overlying mucosa
  • The tumor cells were positive for calretinin and D2-40 (and cytokeratin), negative for mucicarmine, CEA, CD45, CD117, Ber-EP4, cytokeratin 7 and cytokeratin 20; a diagnosis of metastatic mesothelioma was made
  • CT showed nodular thickening of the left lower pleura, described as compatible with primary pleural mesothelioma
  • The patient was lost to follow-up
• The authors' conclusion: The authors concluded that metastatic disease is uncommon at initial diagnosis of malignant mesothelioma, that this case presented as multiple gastric and colonic polyps, and that a full clinical history, radiological correlation and immunohistochemical studies are needed for diagnosis

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Mesothelioma, Epithelium, Calretinin, Podoplanin (D2-40), Ber-EP4, Pleura.

Related studies

• Metastatic malignant mesothelioma presenting as colonic polyps — A.V. Masangkay, M. Susin, et al. (1997)
• Metastasis of pleural mesothelioma presenting as bleeding colonic polyp — S. Sibio, P. Sammartino, et al. (2011)
• Malignant peritoneal mesothelioma giving rise to multiple intestinal polyps — F.G. Mayall, A.R. Gibbs (1991)
• Clinical and pathological characteristic of metastatic malignant mesothelioma initially diagnosed by lymph node biopsy — X.L. Zhu, L.M. Gao, et al. (2017)
• Diffuse Pleural Mesothelioma Initially Presenting as Cervical Lymphadenopathy: A Report of a Rare Case — K. Saha, S. Ghosh, et al. (2026)
• Benign Multicystic Peritoneal Mesothelioma Presenting as a Colonic Mass — K. Pierre, N.F. Gomez, et al. (2021)

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