Peritoneal Mesothelioma in a Patient with Long-Standing Crohn's Disease: Cause or Coincidence?

Our plain-English summary of Peritoneal Mesothelioma in a Patient with Long-Standing Crohn's Disease: Cause or Coincidence?, by R. Prata, P. Lages Martins, V.P. Borges, et al (GE Portuguese Journal of Gastroenterology, 2025).

The study

• Authors: R. Prata, P. Lages Martins, V.P. Borges, P. Botelho, A. Figueiredo, J. Ramos
• Journal: GE Portuguese Journal of Gastroenterology
• Published: 2025;32(5):314-319
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction: Peritoneal mesothelioma (PeM) is a rare cancer of the peritoneal lining. Unlike pleural mesothelioma, PeM is less frequently linked to asbestos exposure. Chronic serosal inflammation, as seen in Crohn's disease (CD), has been proposed as a contributing factor in its carcinogenesis.

Case Presentation: A male with a long-standing history of ileal CD presented with recurrent episodes of intestinal subocclusion. Imaging showed complex active ileal CD, new-onset ascites, and peritoneal densification. Intraoperatively, a small bowel mass adherent to the sigmoid colon and millimetric nodules of the peritoneum were identified. Histology of the resected segment showed CD-related changes and multiple areas of epithelioid mesothelioma, despite no asbestos exposure. He received cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, with no signs of recurrence after 15 months.

Discussion/conclusion: We present a rare case of non-asbestos-related PeM in a patient with long-standing active CD, highlighting the diagnostic challenges and possible link between chronic serosal inflammation and PeM.

© 2025 The Author(s). Published by S. Karger AG, Basel.

In plain English

This was a case report of one patient treated in Lisbon, Portugal. A 46-year-old man had been diagnosed with Crohn's disease at age 19; it was described as long-standing stricturing and fistulizing disease of the ileum (the last part of the small bowel). He came in with six months of recurring partial bowel blockage. A CT scan showed thickening of the ileum wall, with adhesions and a fistula to the sigmoid colon, new fluid in the abdomen, and densification of the peritoneum (the abdominal lining). At surgery, doctors found a small bowel mass and tiny peritoneal nodules. The removed bowel showed Crohn's changes but no precancerous changes. It also showed multiple areas of epithelioid mesothelioma on the small bowel's outer surface. The patient had no history of asbestos exposure. He then had cytoreductive surgery with heated chemotherapy into the abdomen. At 15 months he had no symptoms and no sign of recurrence. The authors wrote that evidence suggests a link between chronic inflammation of the outer lining and peritoneal mesothelioma. They stated that a cause-and-effect link cannot be inferred.

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 46-year-old man from Lisbon, Portugal, first diagnosed with Crohn's disease at age 19, presenting with long-standing stricturing and fistulizing ileal Crohn's disease
• Exposure: No asbestos exposure. The condition considered was long-standing Crohn's disease with chronic inflammation of the bowel's outer lining (serosa).
• Main results:
  • CT enterography showed significant thickening of the distal ileum wall with adhesive and fistulizing changes to the sigmoid colon, new-onset ascites and peritoneal densification
  • At surgery, a small bowel mass adherent to the sigmoid colon, millimetric peritoneal nodules and ascites were found
  • The resected bowel segment showed changes consistent with Crohn's disease, without dysplasia
  • Multiple foci of epithelioid mesothelioma were found in the small bowel serosa. They invaded up to the muscularis propria, stained positive for calretinin and CK7, and stained negative for CK20.
  • The patient underwent cytoreductive surgery combined with hyperthermic intraoperative peritoneal perfusion with chemotherapy
  • At the 15-month follow-up the patient was asymptomatic with no signs of recurrence
• The authors' conclusion: The authors presented this as a rare case of non-asbestos-related peritoneal mesothelioma in long-standing active complex ileal Crohn's disease. They wrote that evidence suggests a link between chronic serosal inflammation and peritoneal mesothelioma. They added that the mechanisms and clinical significance are unclear and that a cause-effect association cannot be inferred.
• Limitations the authors state:
  • The rarity of peritoneal mesothelioma limits understanding of its epidemiological features
  • A cause-effect association between Crohn's disease and peritoneal mesothelioma cannot be inferred from this case

Topics

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Standing, Pleural Mesothelioma, Asbestos Exposure, Inflammation, Carcinogenesis, Ascites, Peritoneum.

Related studies

• Malignant peritoneal mesothelioma and Crohn disease — K.J. Butnor, E.N. Pavlisko, et al. (2017)
• Atypical abdominal pain: uncovering malignant peritoneal mesothelioma in suspected Crohn's disease: a case report — C. Loehr, L. Boudreaux, et al. (2025)
• Immunotherapy of mesothelioma: the evolving change of a long-standing therapeutic dream — L. Calabrò, G. Bronte, et al. (2023)
• "Mesothelioma of the atrioventricular node" with long-standing complete heart block. Report of a case — I.R. Wanless, B.W. Mielke, et al. (1975)
• Benign multicystic peritoneal mesothelioma: a rare cause of intra-abdominal cystic disease — B. Campbell, D. Mehanna, et al. (2017)
• Long crocidolite asbestos fibers cause polyploidy by sterically blocking cytokinesis — C.G. Jensen, L.C. Jensen, et al. (1996)

Browse return to medical research.