Multiple malignant epithelioid mesotheliomas of the liver and greater omentum: a case report and review of the literature

Our plain-English summary of Multiple malignant epithelioid mesotheliomas of the liver and greater omentum: a case report and review of the literature, by K. Minami, H. Okumura, K. Hiwatashi, et al (Surgical Case Reports, 2017).

The study

• Authors: K. Minami, H. Okumura, K. Hiwatashi, S. Matsukita, T. Setoyama, K. Minamimagari, Y. Tsuruta, I. Kanetsuki, Y. Ogura, S. Maenohara, S. Natsugoe
• Journal: Surgical Case Reports
• Published: 2017;3(1):66
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Malignant mesothelioma commonly arises from the pleura, but can also arise from the peritoneum, pericardium, and tunica vaginalis testis. However, malignant mesothelioma of the liver is extremely rare and coexistence with malignant mesothelioma of the greater omentum has not been described in the literature. In this case report, we present a case of multiple malignant mesothelioma of the liver and greater omentum.

Case Presentation: A 36-year-old woman was admitted to our hospital for the evaluation of an elastic hard mass in the right upper abdomen. Abdominal contrast computed tomography showed a cystic mass measuring 13 × 14 × 11 cm in the right liver lobe with enhanced mural nodule. Abnormal accumulation was identified in the liver and lower abdominal area on 18F-fluorodeoxyglucose positron emission tomography. The patient underwent hepatectomy of the posterior segment and partial resection of the omentum. The final pathological diagnosis was low-grade multiple malignant epithelioid mesothelioma based on characteristic immunohistochemical findings. As of 6 months postoperatively, the patient has shown no disease recurrence.

Conclusions: We present the first case of a 36-year-old woman with multiple malignant mesothelioma of the liver and greater omentum.

In plain English

This article was a case report from Kagoshima Kouseiren Hospital in Japan, with a short review of earlier published cases. A 36-year-old woman with no previous disease had two months of abdominal and back pain and a hard mass in the right upper abdomen. A CT scan showed a cystic mass measuring 13 × 14 × 11 cm in the right lobe of the liver. A PET scan also showed abnormal uptake in the lower abdomen. Surgeons removed part of the liver and part of the omentum, a fatty layer inside the abdomen. Pathologists diagnosed multiple low-grade malignant epithelioid mesothelioma in the liver and the greater omentum. A marker of tumor cell growth (Ki-67) was 5–6%. Six months after surgery she had no recurrence. The article does not say whether she had been exposed to asbestos. Among 12 earlier published cases of mesothelioma inside the liver, the authors found 1 with a clear history of asbestos exposure, 8 without, and 3 not evaluated. The authors judged the tumors to be multiple separate mesotheliomas but said they could not rule out spread.

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 one patient, with a review of previously published case reports
• Who was studied: One 36-year-old woman treated at Kagoshima Kouseiren Hospital, Japan, with a 2-month history of abdominal and back pain and no prior disease. The review covered 12 earlier published cases of primary intrahepatic malignant mesothelioma (6 men, 6 women).
• Exposure: The article does not report whether this patient had any asbestos exposure. Among the 12 earlier published liver cases reviewed, 1 had a clear history of asbestos exposure, 8 had none, and 3 were not evaluated.
• Main results:
  • In this patient, contrast CT showed a cystic mass of 13 × 14 × 11 cm in the right lobe of the liver.
  • In this patient's surgical specimens, the liver tumor measured 18 × 15 cm and contained bloody fluid. Two omental tumors measured 2.1 × 1.3 cm and 0.3 × 0.3 cm.
  • The final diagnosis for this patient was multiple low-grade malignant epithelioid mesothelioma, based on microscopic and immunohistochemical findings. Tumor cells were positive for calretinin, among other markers.
  • This patient's Ki-67 index (a measure of tumor growth activity) was 5–6%. The authors noted that the index in typical malignant mesothelioma is 15–20%.
  • This patient had no relapse 6 months after surgery.
  • In the 12 earlier reported liver cases, the mean age was 58.4 years (range 41 to 68). The authors stated their patient was the youngest female case.
• The authors' conclusion: The authors concluded that the liver and omental tumors should be diagnosed as multiple mesotheliomas, based on matching pathology, fibrous capsules and low growth activity. They added that they could not rule out spread (dissemination). They described the case as the first reported with mesothelioma of both the liver and the greater omentum.
• Limitations the authors state:
  • The authors stated it was difficult to tell whether the omental tumor was a separate tumor or a spread from the liver tumor.

Topics

Medical terms in this study, explained in our Lexicon: Epithelioid, Mesothelioma, Omentum, Pleura, Peritoneum, Pericardium, Tunica Vaginalis.

Related studies

• Primary diffuse malignant epithelioid peritoneal mesothelioma of the greater omentum in an asbestos-naive patient: a case report — X. Gan, Y. Tuo, et al. (2026)
• Gray scale sonographic presentation of a mesothelioma of the greater omentum — J.M. Shah, D.L. King (1979)
• Primary malignant mesothelioma of the greater omentum: report of a case — Y.C. Liu, Y.L. Kuo, et al. (2004)
• Secondary malignant peritoneal mesothelioma of the greater omentum after therapy for primary pleural mesothelioma — A. Gutzeit, C. Reischauer, et al. (2013)
• Primary Peritoneal Mesothelioma Affecting the Greater Omentum That Mimicked an Omental Infarction: A Case Report — J.C. Cravero, T. Yakubik, et al. (2024)
• Benign Cystic Mesothelioma of the Peritoneum Arising at the Greater Omentum in a 14-Year-Old Boy — Y. Hirayama, N. Higashidate, et al. (2025)

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