Localized biphasic malignant mesothelioma presenting as a giant pelvic wall mass: a rare case report and literature review

Our plain-English summary of Localized biphasic malignant mesothelioma presenting as a giant pelvic wall mass: a rare case report and literature review, by Y. Liu, J. Wu, Y. Zhao, et al (BMC Medical Imaging, 2020).

The study

• Authors: Y. Liu, J. Wu, Y. Zhao, P. Zhang, Z. Hua, W. Dong, T. Lin, A. Liu
• Journal: BMC Medical Imaging
• Published: 2020;20(1):48
• Type of article: Case report, Review
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Localized biphasic MPeM is rare in clinical practice, we reviewed 8 cases of localized biphasic MPeM (including our present case), and summarized the clinical and imaging features of the disease.

Case Presentation: We reported a 79-year-old man with chief complaint of a narrowing in the caliber of the stool for one year. A soft tissue shadow was occasionally found by CT examination in the right pelvic wall, and it was diagnosed as localized biphasic malignant peritoneal mesothelioma (MPeM) by postoperative pathology. Radical excision was performed and no radio-chemotherapy was applied. Nearly six years after surgery, the mass was significantly enlarged, and the neighboring tissues including rectum, prostate, seminal vesicle, and right ischial ramus were all infiltrated. The patient was in the end stage of cancer with poor prognosis.

Conclusions: The localized biphasic MPeM may show following characteristics: (1) with heterogeneous low-density and obscure margin; (2) with low incidence rate of ascites; (3) with few central hemorrhage and necrosis; (4) with few calcified structures; (5) with mild to moderate heterogeneous delayed enhancement on contrast-enhanced CT. The imaging characteristics can provide further information for the diagnosis of localized biphasic MPeM in the future.

In plain English

This was a case report with a review of published cases, from a hospital in Dalian, China. It described a 79-year-old man who had a narrowing of his stool for about a year and no history of asbestos exposure. A CT scan found a 7.3 × 5.3 cm mass in the right pelvic wall. It was surgically removed about six months later. Pathology showed localized biphasic malignant peritoneal mesothelioma, a mix of epithelial and sarcomatoid cell types. He had no radiotherapy or chemotherapy right after the operation. The tumor returned four years after surgery; three chemoembolization treatments then relieved his symptoms. Nearly six years after surgery the tumor had grown and invaded nearby tissues, and he was in the last stage of the disease. The authors reviewed eight cases, including this one; two (25%) had a history of asbestos exposure. The authors concluded that this tumor may show uneven low density and unclear margins on CT, with seldom fluid in the abdomen, central bleeding and tissue death, or calcification. However, their own review found central bleeding and tissue death in 6 of 8 cases (75%).

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 literature review of 8 cases of localized biphasic malignant peritoneal mesothelioma (7 published cases plus the present case)
• Who was studied: One 79-year-old man seen at the First Affiliated Hospital of Dalian Medical University, China. The review covered 8 cases (5 males, 3 females) aged 41 to 79 years, median age 69.
• Exposure: The present patient had no history of asbestos exposure. In the 8 reviewed cases, 2 had a history of asbestos exposure. No fiber types are named.
• Main results:
  • Present case: initial CT showed an oval right pelvic wall mass of 7.3 × 5.3 cm with a well-defined boundary and no calcification.
  • Present case: after surgical removal, tumor cells were positive for CD34, calretinin, EMA, MC and Vimentin, and the tumor was considered biphasic malignant mesothelioma.
  • Present case: the patient did not receive radiotherapy or chemotherapy right after the initial surgery.
  • Present case: four years after surgery, a recurrent mass measuring 7.89 × 10.41 cm was found in the same position.
  • Present case: after the recurrence, the patient underwent three chemoembolization treatments and his symptoms were significantly relieved.
  • Present case: nearly six years after surgery, the patient was in the last stage of the disease with cachexia.
  • Review of 8 cases: 2 patients (25%) had a history of asbestos exposure.
  • Review of 8 cases: the patients ranged in age from 41 to 79 years.
  • Review of 8 cases: on CT without contrast, masses were heterogeneous and low-density in 7/8 cases (88%).
  • Review of 8 cases: obscure margins were seen in 5/8 (63%) cases.
  • Review of 8 cases: central hemorrhage and necrosis occurred in 6/8 (75%) cases.
  • Review of 8 cases: only two (25%) cases had ascites.
  • Review of 8 cases: calretinin was positive in 8/8 (100%) cases.
• The authors' conclusion: The authors concluded that localized biphasic malignant peritoneal mesothelioma may show heterogeneous low density and obscure margins, a low rate of ascites, little central hemorrhage and necrosis, few calcifications, and mild to moderate heterogeneous delayed enhancement on contrast-enhanced CT. They also suspected that the prognosis is generally poor.
• Limitations the authors state:
  • The authors noted that, because there are so few cases, few specific imaging findings were found.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma, Peritoneal mesothelioma.

Medical terms in this study, explained in our Lexicon: Biphasic Mesothelioma, Mesothelioma, Peritoneal Mesothelioma, Pathology, Chemotherapy, Prognosis, Incidence, Ascites.

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• Localized biphasic malignant peritoneal mesothelioma presenting as a rectal tumor — K. Saisho, S. Fujiwara, et al. (2020)
• Pelvic mass-like florid cystic endosalpingiosis of the uterus: a case report and a review of literature — P. Rosenberg, L. Nappi, et al. (2011)
• Multicystic benign cystic mesothelioma presenting as a pelvic mass — M. Momeni, E. Pereira, et al. (2014)
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