Challenging Diagnostic Process for a Malignant Peritoneal Mesothelioma Patient With Ascites and Pleural Effusion: A Case Report and Review of the Literature

Our plain-English summary of Challenging Diagnostic Process for a Malignant Peritoneal Mesothelioma Patient With Ascites and Pleural Effusion: A Case Report and Review of the Literature, by X. Zeng, K. Xu, L. Zhang, et al (Frontiers in Oncology, 2022).

The study

• Authors: X. Zeng, K. Xu, L. Zhang, X. Huang
• Journal: Frontiers in Oncology
• Published: 2022;12:784064
• Type of article: Case report
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant peritoneal mesothelioma (MPM) is a sporadic and fatal disease of the peritoneal lining. Its diagnosis has been known to be challenging, time-consuming, and money-consuming. In this paper, we report an MPM case of a 58-year-old man with severe abdominal distension. After he had received all kinds of auxiliary examination, including computed tomography scans of the chest and whole abdomen, examinations of peripheral and pleural fluid, positron emission tomography, and twice fine-needle peritoneal biopsies, his disease still could not be confirmed. Eventually, the patient was diagnosed with MPM through laparoscopic biopsy and IHC. From this case, we concluded that clinicians can gradually discover and diagnose the disease through 1) high platelet and CA125 levels and CT imaging results, 2) cytologic examinations of ascites and pleural fluid, 3) peritoneal biopsies (fine-needle biopsy, laparoscopy biopsy), and 4) histopathological examinations and immunohistochemistry findings. The diagnostic process involving this patient can be an example to demonstrate the effectiveness of various auxiliary examination methods in MPM diagnosis.

Copyright © 2022 Zeng, Xu, Zhang and Huang.

In plain English

This article is a case report with a short literature discussion. It describes how doctors at West China Hospital, Sichuan University, diagnosed malignant peritoneal mesothelioma (cancer of the abdominal lining) in a 58-year-old man. The article does not say whether he had ever been exposed to asbestos. He was readmitted with severe abdominal swelling four months after an August 2020 hospital stay. CT showed a large amount of fluid in the abdomen and pelvis, a small amount of fluid around the lungs, and a thickened abdominal lining. His platelets and the tumor marker CA125 were high. Tuberculosis antibodies were found in the fluids, but further tuberculosis tests were negative. Repeated fluid tests, a PET-CT scan and two fine-needle biopsies did not settle the diagnosis. A laparoscopic biopsy with special tissue staining finally showed malignant mesothelioma. He then had chemotherapy, surgery and two more chemotherapy cycles. His latest MRI showed the tumor had shrunk by three-quarters. The authors concluded that blood tests, CT, fluid tests, biopsies and tissue staining can gradually lead to 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 of a single patient, with a brief discussion of published literature (not a systematic review)
• Who was studied: One 58-year-old man treated at the Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, China. He was first hospitalized in August 2020 and readmitted four months later.
• Exposure: The article does not report any asbestos exposure, or any other occupational or environmental history, for this patient. Asbestos is mentioned only in the introduction, as general background drawn from other studies.
• Main results:
  • On readmission, abdominal CT showed a large amount of fluid in the abdomen and pelvis and a small amount of pleural effusion. Enhanced CT showed a thickened peritoneum and omentum.
  • Platelets were markedly raised, at 552 × 10^9 per liter.
  • Tumor markers CA125, CA15-3 and cytokeratin 19 fragment were abnormally high in blood, pleural fluid and ascites. CA125 was 232.00 U/ml in serum, 734.00 U/ml in ascites and 1,079.00 U/ml in pleural fluid; the hospital's normal value in blood is below 24. At the first hospitalization, serum CA125 had been 13.3 U/ml.
  • Tuberculosis antibodies were positive in both pleural fluid and ascites. However, adenosine deaminase levels were 37.8 IU/ml in ascites and 16.2 IU/ml in pleural fluid, which the authors judged not high enough to support tuberculosis, and a later series of tuberculosis tests were all negative.
  • Repeated cytology of the pleural fluid and ascites found only proliferative mesothelial cells.
  • PET-CT showed uneven peritoneal thickening with abnormally increased glucose metabolism. The doctors could not tell whether this was tumor or inflammation.
  • Two fine-needle peritoneal biopsies found some abnormal cells. Staining (PCK, CK7, CK5/6, WT-1, HBME-1 and desmin positive) supported mesothelial cell hyperplasia or mesothelial tumors, but the pathology department reported the tissue was too small to confirm or was useless.
  • Laparoscopy found turbid ascites, extensive adhesions and many nodules, and no primary tumor could be detected. Pathology of the omentum and abdominal wall indicated malignant mesothelioma. Staining was WT-1, CR and CK5/6 positive, CD31 and CDX-2 negative, with a Ki-67 positive rate of about 30%, supporting the diagnosis.
  • Because his peritoneal cancer index was above 30 and he had extensive adhesions, he was not immediately offered surgery with heated intraperitoneal chemotherapy (CRS plus HIPEC). He received four cycles of pemetrexed, cisplatin and bevacizumab, after which the tumor shrank significantly. He then had cytoreductive surgery followed by two cycles of adjuvant chemotherapy.
  • Side effects during chemotherapy were bone marrow suppression, immunodeficiency and difficulty swallowing, which improved with symptomatic treatment. Doses were reduced because of severe bone marrow suppression.
  • The latest MRI showed the tumor inside the abdomen had resolved by three-quarters of its original size, and the ascites and pleural fluid were gone.
• The authors' conclusion: The authors concluded that peritoneal mesothelioma can be gradually discovered and diagnosed through four steps. First, blood and ascites tests (such as high platelet and CA125 levels) and CT imaging. Second, cytology to find unusual cells. Third, peritoneal biopsy (fine-needle and laparoscopic). Fourth, tissue examination with immunohistochemistry to confirm the diagnosis. They also wrote that the patient achieved a fairly satisfactory survival outcome, and that research on treatment holds further promise.
• Limitations the authors state:
  • The report does not give the patient's histological subtype of mesothelioma, because the pathology report did not specify it, although the subtype matters for predicting prognosis.
  • The patient underwent many tests to reach the diagnosis, which was unpleasant and expensive for him and his family.

Topics

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Ascites, Pleural Effusion, Biopsy, Needle Biopsy, Immunohistochemistry.

Related studies

• Retrospective investigation on diagnostic process for benign asbestos pleural effusion (BAPE) using checklist — T. Kishimoto, N. Fujimoto, et al. (2020)
• Malignant Peritoneal Mesothelioma as a Rare Cause of Dyspeptic Complaints and Ascites: A Diagnostic Challenge — S. Marques de Sousa, F. Pereira, et al. (2020)
• Non-Asbestos-Related Malignant Peritoneal Mesothelioma: A Diagnostic Challenge in a Case of Unexplained Ascites — M.A.F. Dar, N. Nasir, et al. (2025)
• From Ascites to Malignant Peritoneal Mesothelioma: The Diagnostic Workup of a Rare Tumor — M. Nastasi, C. Ferrante, et al. (2026)
• Challenging and uncommon diagnosis of long-evolution ascites — M. Gravito-Soares, E. Gravito-Soares, et al. (2017)
• A rare case of primary effusion lymphoma in HIV negative patient: Diagnostic challenges and literature review — P. Malik, S.N. Khader, et al. (2021)

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