Successful Complete Laparoscopic Resection of Benign Peritoneal Multicystic Mesothelioma Adherent to the Ascending Colon: A Case Report

Our plain-English summary of Successful Complete Laparoscopic Resection of Benign Peritoneal Multicystic Mesothelioma Adherent to the Ascending Colon: A Case Report, by Y. Kitamura, M. Miguchi, R. Nagao, et al (Surgical Case Reports, 2025).

The study

• Authors: Y. Kitamura, M. Miguchi, R. Nagao, M. Shinohara, K. Nakashima, M. Hamaoka, M. Hashimoto, T. Misumi, N. Fujikuni, S. Ikeda, Y. Matsugu, K. Mori, T. Nishisaka, H. Nakahara
• Journal: Surgical Case Reports
• Published: 2025;11(1)
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction: Benign peritoneal multicystic mesothelioma (BPMM) is a rare mesothelial tumor with a high local recurrence rate and potential for malignant transformation. It predominantly affects women of reproductive age and is often associated with prior abdominal surgery or inflammation. Complete surgical resection is the standard treatment; however, tumor recurrence remains a concern. BPMM occurring outside the pelvis is extremely rare, and lesions requiring colectomy because of adherence to the gastrointestinal tract are infrequent.

Case Presentation: A 63-year-old woman presented with right lower abdominal pain. She had undergone cervical cancer surgery 20 years ago. Contrast-enhanced CT and MRI revealed multiple well-defined cystic lesions adjacent to the ascending colon. Colonoscopy revealed extrinsic compression, and 18F-fluorodeoxyglucose (18F-FDG)-PET/CT showed no abnormal uptake of 18F-FDG. Given the patient's symptoms, a laparoscopic right hemicolectomy with intracorporeal anastomosis was performed. The cystic lesions were firmly adhered to the appendix, cecum, and ascending colon, requiring en bloc resection. Histopathological and immunohistochemical analyses confirmed a diagnosis of BPMM. The patient had an uneventful postoperative course and was discharged on POD 7. No recurrence was observed during the 1-year follow-up period.

Conclusions: A laparoscopic approach may be a feasible and safe option for complete resection of BPMM as it allows for magnified visualization and careful handling of cystic lesions, avoiding their intraoperative rupture. Given the high recurrence rate of BPMM, close postoperative surveillance is essential. This case illustrates the feasibility of laparoscopic resection for BPMM.

© 2025 The Author(s). Published by Japan Surgical Society.

In plain English

This case report from Hiroshima Prefectural Hospital in Japan described one 63-year-old woman with benign peritoneal multicystic mesothelioma (BPMM). She came to hospital with pain in the lower right abdomen. She had had surgery for cervical cancer 20 years earlier. CT scans showed multiple cystic lesions, the largest 113 mm across, next to the ascending colon. A PET/CT scan showed no increased uptake in the lesions or in other organs. Surgeons removed the right side of the colon by keyhole (laparoscopic) surgery. The cysts were stuck to the appendix, cecum and ascending colon and were hard to separate, so they were removed together with the colon in one piece. Examination of the tissue under the microscope, including special staining, confirmed BPMM. She left hospital on the seventh day after surgery. A CT scan one year later showed no sign of the tumor returning. The authors suggested her earlier cervical cancer surgery might have caused the tumor. The article did not mention asbestos. The authors concluded that a laparoscopic approach may help achieve complete removal, and said checks for recurrence remain essential.

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 63-year-old woman admitted to the surgical department of Hiroshima Prefectural Hospital, Hiroshima, Japan; dates of care not stated
• Exposure: No asbestos exposure is mentioned in the article. The authors suggested the patient's surgery for cervical cancer 20 years earlier might have caused the tumor.
• Main results:
  • CT showed multiple cystic lesions with a maximum diameter of 113 mm next to the ascending colon
  • 18F-FDG PET/CT showed no increased uptake in the lesions or in other organs
  • The patient underwent laparoscopic right hemicolectomy (keyhole removal of the right colon)
  • Because the cysts were difficult to detach, they were removed in one piece (en bloc) with the right-sided colon
  • Under the microscope, the cysts were lined by a single layer of cells without atypia; immunostaining was positive for mesothelial markers; the final diagnosis was BPMM
  • The patient was discharged on postoperative day 7
  • No signs of recurrence were seen on CT one year after surgery
  • Heated chemotherapy inside the abdomen (HIPEC) was not given. The diagnosis had not been confirmed at the time of surgery, and no criteria exist for adding HIPEC during an operation.
• The authors' conclusion: The authors concluded that, for BPMM adherent to the colon, the tumor and the adherent colon should be removed together in one piece. They concluded that a laparoscopic approach may make complete removal easier, because magnification helps the surgeon find and cut out even small cysts.
• Limitations the authors state:
  • The patient had been followed for only one year without recurrence, and the authors stated that continued surveillance for recurrence is essential

Topics

Medical terms in this study, explained in our Lexicon: Multicystic Mesothelioma (MCM), Malignant Transformation, Inflammation, Surgical Resection.

Related studies

• Thinking outside the pelvis: benign peritoneal multicystic mesothelioma of the ascending colon — B. Murphy, M. Ismaeil, et al. (2023)
• A recurrence of benign multicystic peritoneal mesothelioma treated through laparoscopic excision: a case report and review of the literature — T.D. Witek, J.W. Marchese, et al. (2014)
• Rare confounder: benign multicystic peritoneal mesothelioma in a patient with mucinous colon adenocarcinoma — K.K. Patel, G.P. Stinson, et al. (2024)
• Laparoscopic diagnosis and treatment of pelvic benign multicystic mesothelioma associated with high CA19.9 serum concentration — V. Pinto, A.C. Rossi, et al. (2010)
• Multicystic peritoneal mesothelioma treated with complete cytoreductive surgery, peritonectomy and hyperthermic intra-peritoneal chemotherapy-A case report — N. Padmanabhan, H. Ishibashi, et al. (2020)
• Laparoscopic excision of a benign peritoneal cystic mesothelioma — A. Limone, J. Maier, et al. (2010)

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