Cystic epithelioid malignant mesothelioma of the mesentery with rapid postoperative metastasis: an unusual case report

Our plain-English summary of Cystic epithelioid malignant mesothelioma of the mesentery with rapid postoperative metastasis: an unusual case report, by T. Xu, X. Meng, X. Gou, et al (Frontiers in Medicine, 2026).

The study

• Authors: T. Xu, X. Meng, X. Gou, X. Wang, S. Luo, D. Zhang
• Journal: Frontiers in Medicine
• Published: 2026;13:1903020
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Epithelioid malignant mesothelioma is a subtype of peritoneal mesothelioma associated with a relatively better prognosis. Herein, we report a case of epithelioid malignant mesothelioma in a 50-year-old Chinese female without a history of asbestos exposure. The tumor initially presented as a localized cystic mesenteric lesion. However, metastasis to the liver margin was detected 22 days after surgery, accompanied by rapid disease progression within one month. Gross examination revealed a cystic mass. Histologically, the tumor was consistent with epithelioid malignant mesothelioma, a rare pathological finding.

Case Demonstration: A 50-year-old female patient was admitted with a two-month history of right lower quadrant abdominal pain and no reported asbestos exposure. Ultrasound revealed a cystic structure of undetermined nature and origin in the right lower abdomen. Contrast-enhanced magnetic resonance imaging (MRI) of the mid-to-lower abdomen demonstrated a round mass adjacent to the cecum, measuring 47 × 40 × 59 mm. On T1-weighted imaging, the lesion exhibited high signal intensity on in-phase, out-of-phase, and fat-suppressed sequences; on T2-weighted imaging, it appeared isointense to slightly hyperintense. The mass wall was unevenly thickened with irregular margins. The central area of the lesion showed no enhancement and appeared hypointense. The mass was located in the pericecal region, suggesting a cystic mesenchymal tumor. Postoperative pathological examination confirmed the diagnosis of localized epithelioid malignant mesothelioma of the mesentery. Metastasis was detected 22 days after surgery.

Conclusions: We report this rare case of localized malignant mesothelioma to raise awareness among clinical pathologists of this entity, facilitate accurate diagnosis, and help avoid misdiagnosis.

© 2026 Xu, Meng, Gou, Wang, Luo and Zhang.

In plain English

This case report described a 50-year-old Chinese woman with two months of right lower abdominal pain and no history of asbestos exposure. MRI showed a mass near the cecum, the start of the large bowel. The mass was removed by laparoscopic surgery. It was cystic, and it had been opened and its contents had leaked out before the laboratory examined it. Tissue tests led to a diagnosis of localized epithelioid malignant mesothelioma of the mesentery, with the cell-growth marker Ki-67 at 60% in hotspot areas. Twenty-two days after surgery the patient had unexplained fever. CT showed multiple lesions in the right mid-lower abdomen and under the liver margin, raising concern for recurrence or metastasis. These lesions were not biopsied because of the patient's rapid deterioration and institutional resource constraints. The authors speculated that the opened cyst may have helped the tumor spread. They concluded that the prognosis was poor and that necrosis and hemorrhage may be important for prognosis, which needs confirmation. BAP1 and HCG staining and molecular testing were not done.

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 50-year-old Chinese woman
• Exposure: the patient had no history of asbestos exposure
• Main results:
  • The patient was admitted with right lower abdominal pain lasting 2 months
  • MRI showed a mass near the cecum measuring 47 × 40 × 59 mm
  • The cystic tumor was completely removed by laparoscopic surgery
  • On gross examination the cyst had previously been opened and its contents had leaked out
  • Pathological diagnosis: localized epithelioid malignant mesothelioma of the mesentery in the pericecal region
  • Ki-67 was positive in 60% of tumor cells in hotspot areas
  • 22 days after surgery the patient had unexplained fever, and CT showed multiple lesions in the right mid-lower abdomen and under the liver margin, raising concern for recurrence or metastasis
  • The suspected metastases were not confirmed by tissue examination because of the patient's rapid clinical deterioration and institutional resource constraints at that time
  • The authors speculated that rupture of the cystic mass could have released tumor cells and contributed to the rapid spread
• The authors' conclusion: The authors concluded that the prognosis of this case was poor, with metastasis in the short term, and that necrosis and hemorrhage may be important factors in assessing prognosis, although this needs to be confirmed by further studies
• Limitations the authors state:
  • The suspected liver margin metastasis was diagnosed on CT imaging alone, without biopsy confirmation
  • BAP1 immunohistochemistry was not performed
  • HCG immunohistochemistry was not performed because the antibody was not available
  • Molecular testing, including next-generation sequencing and fusion gene detection, was not done because it was not available

Topics

Medical terms in this study, explained in our Lexicon: Epithelioid, Mesothelioma, Mesentery, Metastasis, Peritoneal Mesothelioma, Prognosis, Asbestos Exposure, Disease Progression.

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