Well-differentiated papillary mesothelioma: peritoneal implants are not always metastases in the presence of cancer

Our plain-English summary of Well-differentiated papillary mesothelioma: peritoneal implants are not always metastases in the presence of cancer, by G.W. Irwin, A. Ervine, J.A. Kennedy (Scottish Medical Journal, 2014).

The study

• Authors: G.W. Irwin, A. Ervine, J.A. Kennedy
• Journal: Scottish Medical Journal
• Published: 2014;59(1):e18-21
• Type of article: Case report
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Introduction: Well-differentiated papillary mesothelioma is a rare condition that can cause diagnostic uncertainty. Its appearance resembles metastatic deposits and in the presence of a known primary can often be confused for such.

Case Presentation: In this case, we present a patient who had WDPM in the presence of gastric cancer and emphasise the difficulties in making the diagnosis.

Conclusion: We highlight the need for a high index of suspicion, biopsies at staging laparoscopy and undertake a review of the literature regarding this uncommon condition.

In plain English

This was a case report of one patient. A 68-year-old woman went to a surgical clinic with abdominal pain. She had no history of asbestos exposure. Tests found an adenocarcinoma (a type of cancer) in her stomach. A CT scan also showed two lesions in the fat inside her abdomen, which doctors thought were spread of the stomach cancer. A biopsy taken during keyhole surgery instead showed well-differentiated papillary mesothelioma (WDPM) of the peritoneum, the lining of the abdomen. During later surgery to remove part of her stomach, surgeons found many small nodules on the omentum and other abdominal surfaces. Three tested during the operation showed no spread of the stomach cancer. The final report described these nodules as further deposits of WDPM. The stomach cancer had not spread to any of the 16 lymph nodes examined. After several years with no progression she was discharged, but five years after surgery she was found to have a separate pancreatic cancer. The authors concluded that peritoneal deposits should always be biopsied, even when a primary cancer is known.

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 of a single patient
• Who was studied: One 68-year-old woman seen at a surgical outpatient clinic with abdominal pain
• Exposure: The patient had no history of asbestos exposure. She had been a heavy smoker more than 30 years earlier.
• Main results:
  • A CT scan showed two lesions in the intra-abdominal fat, which were thought to be metastases from the stomach cancer.
  • The omental biopsy from the staging laparoscopy was cytologically bland, with a Ki-67 proliferation index of less than 5%. Its appearance was consistent with WDPM.
  • At surgery there were multiple small nodules on the greater omentum and serosa. Three biopsies sent for frozen section analysis were each negative for metastatic adenocarcinoma.
  • The final pathology showed an intramucosal gastric adenocarcinoma with none of 16 lymph nodes involved (pT1N0M0). The peritoneal and omental lesions were further deposits of WDPM, consistent with an indolent neoplastic process.
  • Regular CT scans over several years showed no progression or recurrence, and she was discharged after three years. Five years after surgery she developed liver metastases from a primary pancreatic cancer, which was different from the gastric cancer and the WDPM.
• The authors' conclusion: The authors concluded that peritoneal deposits should always be biopsied, even when a primary cancer is already known, and that frozen section analysis can distinguish WDPM from metastases.

Topics

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

Medical terms in this study, explained in our Lexicon: Well-Differentiated Papillary Mesothelioma, Stomach Cancer, Staging.

Related studies

• Peritoneal well-differentiated papillary mesothelioma coexisting with endometrial adenocarcinoma mimicking peritoneal carcinomatosis: A case report — Y.Y. Chen, P.C. Li, et al. (2020)
• Simultaneous occurrence of a rectal carcinoma and a diffuse well differentiated papillary mesothelioma of the peritoneum — G.R. Jatzko, J. Jester (1997)
• Collagenous Spherulosis in Well-Differentiated Papillary Mesothelioma in a Female With Multilocular Peritoneal Inclusion Cysts — B. AbdullGaffar, L.G. Raman (2019)
• Benign papillary mesothelioma of the peritoneum: a consideration in the differential diagnosis of peritoneal implants — G. Tzanakakis, K.S. McCully, et al. (1989)
• Well-differentiated papillary mesothelioma of the peritoneum: a diagnostic dilemma on fine-needle aspiration cytology — J.G. Nasit, G. Dhruva (2014)
• Fine needle aspiration cytology of well-differentiated papillary mesothelioma: a case report — Y. Gong, R. Ren, et al. (2005)

Browse more research in Scottish Medical Journal, or return to medical research.