Incidental finding of multiple well-differentiated papillary mesotheliomas in peritoneum

Our plain-English summary of Incidental finding of multiple well-differentiated papillary mesotheliomas in peritoneum, by M. Jakobsen, B. Engvad, T. Jensen, et al (APMIS, 2016).

The study

• Authors: M. Jakobsen, B. Engvad, T. Jensen, N. Marcussen
• Journal: APMIS
• Published: 2016;124(4):333-4
• Type of article: Case report
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We present a case of multiple well-differentiated papillary mesotheliomas (WDPM) in the peritoneum found incidentally in a 63-year-old man with urothelial carcinoma of the bladder. When multiple tumors are seen, malignant mesothelioma should be excluded by histopathological examination as this may have a similar focal appearance to WDPM. True stromal invasion is by far the most reliable criterion of mesothelial malignancy. In doubtful cases, a conservative diagnostic approach has been recommended. Compared to malignant mesotheliomas, WDPMs are rare and have a relatively indolent clinical course with a good prognosis. Great care is needed when diagnosing mesothelial proliferations, given the crucial nature of a benign vs malignant diagnosis. No standardized treatment has yet been established.

© 2016 APMIS. Published by John Wiley & Sons Ltd.

In plain English

This article was a case report about one patient. A 63-year-old man with urothelial carcinoma of the bladder (a cancer of the bladder lining) had his urinary bladder surgically removed. When the removed bladder was examined, the bladder cancer was found to be in complete remission. However, the peritoneum (the membrane lining the abdomen) covering the back of the bladder had 23 small brown and grey papillary (finger-like) growths, each 5 to 8 mm across. The surrounding lining looked normal. Under the microscope, each growth had a thin fibrous core covered by a single layer of mesothelial cells that looked benign. None of the growths had grown into the underlying tissue, which is known as stromal invasion. The growths were diagnosed as multiple well-differentiated papillary mesotheliomas. The authors concluded that great care is needed when diagnosing such growths, because whether they are benign or malignant matters for the patient's further care. They also concluded that when several tumors are seen, malignant mesothelioma should be ruled out by microscopic examination. The article did not mention asbestos or any other exposure.

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
• Who was studied: One 63-year-old man with urothelial carcinoma of the bladder; no dates given
• Main results:
  • Examination of the removed bladder showed complete remission of the urothelial carcinoma
  • The peritoneum lining the back of the bladder had 23 brown and grey papillae, 5 to 8 mm in diameter
  • The surrounding mesothelium was unremarkable
  • Microscopically, the tumors had a thin fibrous core lined by a single layer of cuboidal mesothelial cells with benign nuclear features
  • No stromal invasion was seen, and the diagnosis of well-differentiated papillary mesotheliomas was given
• The authors' conclusion: The authors concluded that great care is needed when diagnosing mesothelial proliferations, because a benign versus malignant diagnosis is crucial to further patient management. They also concluded that malignant mesothelioma should be excluded by histopathological examination when multiple tumors are seen.

Topics

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

Medical terms in this study, explained in our Lexicon: Well-Differentiated Papillary Mesothelioma, Peritoneum, Carcinoma, Malignant Mesothelioma, Prognosis.

Related studies

• Well-differentiated papillary mesothelioma of the peritoneum: a diagnostic dilemma on fine-needle aspiration cytology — J.G. Nasit, G. Dhruva (2014)
• Spontaneous urinary bladder perforation: An unusual presentation of well-differentiated papillary peritoneum mesothelioma — A. Serao, F. Ambrosini, et al. (2022)
• Collagenous Spherulosis in Well-Differentiated Papillary Mesothelioma in a Female With Multilocular Peritoneal Inclusion Cysts — B. AbdullGaffar, L.G. Raman (2019)
• Aberrant Pax-8 expression in well-differentiated papillary mesothelioma and malignant mesothelioma of the peritoneum: a clinicopathologic study — D. Xing, N. Banet, et al. (2018)
• First somatic mutation of E2F1 in a critical DNA binding residue discovered in well-differentiated papillary mesothelioma of the peritoneum — W. Yu, W. Chan-On, et al. (2011)
• Clinicopathological Characteristics of Well-differentiated Papillary Mesothelioma of The Peritoneum: A Single-institutional Experience of 12 Cases — M. Kim, H.S. Kim (2019)

Browse more research in APMIS, or return to medical research.