Diffuse Peritoneal Malignant Mesothelioma Presenting with Abnormal Uterine Bleeding: Case Report

Our plain-English summary of Diffuse Peritoneal Malignant Mesothelioma Presenting with Abnormal Uterine Bleeding: Case Report, by I. Rizzuto, T. Power, M.K. Oehler (Case Reports in Oncology, 2022).

The study

• Authors: I. Rizzuto, T. Power, M.K. Oehler
• Journal: Case Reports in Oncology
• Published: 2022;15(1):251-256
• Type of article: Case report
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

This report describes a highly unusual case of malignant peritoneal mesothelioma (MPM), who presented with abnormal menstrual bleeding due to diffuse infiltration of the uterus. MPM is a rare entity, which on initial clinical presentation can be indistinguishable from a primary gynecological malignancy such as ovarian cancer. As differential diagnosis is challenging among primary care physicians, gynecologists, gynecological oncologists, and pathologists, misdiagnosis and subsequent mismanagement are not uncommon. Immunohistochemical stains were required in our case to help to make the final diagnosis. We included multiple mesothelial markers such as calretinin, CK5/6, WT-1, and D240 in our analysis, in addition to epithelial markers such as Claudin-4, BerEP4, B72.3, and PAX-8, to exclude metastatic adenocarcinoma.

Copyright © 2022 by S. Karger AG, Basel.

In plain English

This case report from Adelaide, Australia, described a 37-year-old woman with three months of heavy, painful periods. Scans showed a thickened uterine lining and peritoneal thickening, and her CA125 tumor marker was normal. Tissue scraped from the uterus contained small tumor fragments. These were first interpreted as a rare, usually slow-growing uterine tumor similar to an ovarian sex cord tumor. During surgery, the team found abdominal fluid, tumor covering the omentum (a fatty lining in the abdomen) and small pelvic nodules. They removed the uterus, fallopian tubes and omentum. The main tumor was in the omentum and measured up to 70 mm. The tumor was epithelioid. Staining pointed to malignant peritoneal mesothelioma and showed loss of BAP1 staining in the cell nuclei. Under the microscope, its features were consistent with low-grade cancer. Tumor was also found in patches in the body of the uterus and the cervix. The patient reported no personal or family history of asbestos exposure. The authors concluded that this cancer remains hard to diagnose. They said the possible alternative diagnoses should include spread of gynecological and peritoneal cancers, lymphomas and tuberculous peritonitis.

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 (one patient)
• Who was studied: One 37-year-old Caucasian woman treated at the Royal Adelaide Hospital, Adelaide, Australia; dates of care not given (published 2022)
• Exposure: No asbestos exposure was identified: the patient reported no personal or family history of exposure (the article's wording is 'exposure to asbestosis')
• Main results:
  • Tumor fragments in the uterine curettage stained positive for AE1/3, calretinin and CD10 and were at first interpreted as a uterine tumor similar to an ovarian sex cord tumor
  • At surgery, opaque ascites and omental caking were found, along with multiple small nodules on the pelvic peritoneal surfaces
  • The hysterectomy specimen showed patchy involvement of the uterine corpus and cervix by an apparently metastatic epithelioid malignancy
  • The primary tumor was in the omentum and measured up to 70 mm
  • The tumor was negative for PAX-8 and Claudin-4 and showed loss of nuclear BAP1 staining; it was positive for calretinin, CK5/6, D240 and CK7. The authors judged these features indicative of malignant peritoneal mesothelioma
  • The tumor's microscopic features (moderate nuclear atypia, no necrosis) were consistent with a WHO low-grade malignancy
  • CA125 was the only tumor marker tested and was normal (23 kU/L)
  • The patient was scheduled for neoadjuvant chemotherapy with cisplatin and alimta before cytoreductive surgery and HIPEC
  • The patient declined genetic counseling, which the authors raised because of a possible BAP-1-associated tumor syndrome
  • The authors stated that, to their knowledge, this was only the second reported case of this cancer mainly involving the uterus in a young patient
• The authors' conclusion: The authors concluded that malignant peritoneal mesothelioma remains challenging to diagnose. They said the differential diagnosis should include intraperitoneal spread of gynecological and peritoneal malignancies, lymphomas and tuberculous peritonitis

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Peritoneal Mesothelioma, Ovarian Cancer, Differential Diagnosis, Misdiagnosis, Calretinin, Wilms Tumor 1 (WT-1), Claudin-4.

Related studies

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• What caused gastrointestinal bleeding in a woman with a history of pleural mesothelioma? Metastatic diffuse epithelioid mesothelioma — F. Iafrate, S. Sibio, et al. (2010)
• "Signet-ring" cells--a caveat in the diagnosis of a diffuse peritoneal mesothelioma occurring in a lady presenting with recurrent ascites: an unusual case report — B. Rekhi, S. Pathuthara, et al. (2010)
• Diffuse Malignant Peritoneal Mesothelioma Presenting with Psammomatous Calcification on a Cervical Smear — A. Tan, P. Cohen, et al. (2015)
• Diffuse malignant peritoneal mesothelioma presenting as intestinal obstruction — J. Griniatsos, S. Sougioultzis, et al. (2009)
• Diffuse malignant peritoneal mesothelioma presenting as small bowel obstruction — A.R. Tagliaferri, G. Melki, et al. (2023)

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