Diffuse malignant peritoneal mesothelioma mimicking ovarian cancer

Our plain-English summary of Diffuse malignant peritoneal mesothelioma mimicking ovarian cancer, by Z.I. Houssaini, H.E. Agouri, S. Amalik, et al (Radiology Case Reports, 2022).

The study

• Authors: Z.I. Houssaini, H.E. Agouri, S. Amalik, S. Khouchoua, H. Jerguigue, R. Latib, B.E. Khannoussi, Y. Omor
• Journal: Radiology Case Reports
• Published: 2022;17(3):779-783
• Type of article: Case report
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Diffuse malignant peritoneal mesothelioma (DMPM) and peritoneal carcinomatosis have similar computed tomography imaging features. Peritoneal carcinomatosis is a known metastatic site for many malignancies and particularly gastrointestinal tract and ovarian cancers. Also, DMPM can masquerade as an ovarian epithelial neoplasm, with very similar clinical presentation and an overlap in imaging findings. When no evident primary tumor is detected other than the peritoneal disease, primary malignant mesothelioma should be considered. Since accurate diagnosis is essential for treatment management, the gold standard in differentiating between these two entities lies in histological analysis. We report a case of DMPM that was initially misdiagnosed as an ovarian cancer, where the biopsy of a peritoneal nodule was able to correct and confirm the diagnosis of DMPM.

© 2021 The Authors. Published by Elsevier Inc. on behalf of University of Washington.

In plain English

This was a case report about one patient, from the National Institute of Oncology, Ibn Sina Hospital, in Rabat, Morocco. A 42-year-old woman with no past medical history had pelvic pain and a steadily swelling abdomen for 3 months. Scans showed a large amount of fluid in the abdomen, nodules and thickening of the abdominal lining (the peritoneum), and masses in both ovaries. Doctors first suggested ovarian cancer that had spread to the peritoneum. A needle biopsy of a peritoneal nodule, guided by ultrasound, was then examined under the microscope with special stains. The diagnosis was changed to malignant peritoneal mesothelioma, epithelioid type, with spread to the ovaries. Only afterwards did the patient report an occupational exposure, which the article calls exposure to "asbestosis." The article gave no job, fiber type or amount. The authors concluded that this mesothelioma should be considered when no clear primary tumor is found in patients with known asbestos exposure. They also concluded that tissue examination remains the gold standard for telling it apart from spread cancer. A single case cannot show how often this happens.

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 42-year-old woman with no past medical history, seen at the National Institute of Oncology, Ibn Sina Hospital, Rabat, Morocco, with pelvic pain and progressive abdominal distension for 3 months
• Exposure: Occupational exposure reported by the patient after the diagnosis. The article words it as exposure to "asbestosis" and gives no job, fiber type, duration or dose.
• Main results:
  • Abdominopelvic CT showed extensive peritoneal disease with large-volume ascites, peritoneal nodules, irregular omental thickening and masses in both ovaries.
  • Ovarian carcinoma with peritoneal involvement was the diagnosis first suggested.
  • On immunohistochemistry of the biopsy, the tumor stained positive for the mesothelial markers Wilms' tumor 1 antigen and calretinin, and for carcinoma markers (epithelial membrane antigen, cytokeratin 7, cytokeratin 5/6, pancytokeratin AE1/AE3). Hormone receptors and inhibin were negative.
  • The final diagnosis was malignant peritoneal mesothelioma, epithelioid type, with ovarian metastasis.
• The authors' conclusion: The authors concluded that diffuse malignant peritoneal mesothelioma and peritoneal carcinomatosis look very similar on imaging. They said the diagnosis should be considered when no evident primary tumor is found in patients with known asbestos exposure, and that tissue examination remains the gold standard for telling the two apart.

Topics

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Ovarian Cancer, Neoplasm, Mesothelioma, Biopsy.

Related studies

• Benign multicystic peritoneal mesothelioma mimicking recurrence of an ovarian borderline tumor: a case report — S. Takemoto, R. Kawano, et al. (2012)
• Thrombocytosis as a paraneoplastic syndrome in metastatic malignant peritoneal mesothelioma of biphasic morphology mimicking ovarian adenocarcinoma: A case report — M.S. Alhamadh, R.B. Alanazi, et al. (2023)
• Metastatic primary peritoneal malignant mesothelioma mimicking primary diffuse gastric carcinoma: a rare encounter in gastric biopsy — Y. Yang, D. Gunawardane, et al. (2017)
• p16/CDKN2A FISH in Differentiation of Diffuse Malignant Peritoneal Mesothelioma From Mesothelial Hyperplasia and Epithelial Ovarian Cancer — T. Ito, M. Hamasaki, et al. (2015)
• Mesothelial neoplasms presenting as, and mimicking, ovarian cancer — H. Mani, M.J. Merino (2010)
• Malignant mesothelioma mimicking ovarian cancer — M.J. Merino (2010)

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