Primary peritoneal epithelioid mesothelioma of clear cell type with a novel VHL gene mutation: a case report

Our plain-English summary of Primary peritoneal epithelioid mesothelioma of clear cell type with a novel VHL gene mutation: a case report, by A. Smith-Hannah, R. Naous (Human Pathology, 2019).

The study

• Authors: A. Smith-Hannah, R. Naous
• Journal: Human Pathology
• Published: 2019;83:199-203
• Type of article: Case report
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Clear cell variant of epithelioid mesothelioma is an extremely rare tumor with only isolated cases reported so far in the peritoneum. Here, we report a case of peritoneal epithelioid mesothelioma, clear cell variant, in a 63-year-old female patient with a novel VHL gene mutation and an unusual indolent clinical course. The patient, who has no clinical history of asbestos exposure, presented with a 27.2-cm upper abdominal mass and a 5.5-cm liver lesion. Retrospective review of the patient's abdominal computed tomographic scan 4 years ago showed 2 small abdominal lesions that were felt clinically to represent hemangiomas. These were retrospectively considered to have grown in size and represented the current abdominal mass. Both masses were subsequently biopsied and showed a proliferation of monomorphic epithelioid cells with distinct cell membranes, fine chromatin, and clear to finely vacuolated pale eosinophilic cytoplasm arranged in nests and solid sheets. Immunohistochemical staining confirmed it to be malignant mesothelioma. Clear cell variant of peritoneal epithelioid mesothelioma should always be considered in patients with an abdominal or pelvic mass with clear cell features. Given the rarity of such entity, its clinical course and prognosis remains unclear.

Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

In plain English

This article is a case report about one patient, a 63-year-old woman, with a rare cancer: primary peritoneal epithelioid mesothelioma of the clear cell type. The article states she had no clinical history of asbestos exposure. She saw her doctor for abdominal and right flank pain, and a CT scan found a 27.2 cm abdominal mass and a 5.5 cm liver lesion. Two abdominal lesions seen on a January 2014 scan had been thought likely to be hemangiomas. Doctors now judged these were the current mass, grown over several years. Biopsies and many tissue stains led to the mesothelioma diagnosis. Genetic testing found an alteration in the VHL gene, which the authors called a novel finding in malignant mesothelioma. A clinical PCR panel found none of six common mesothelioma-associated alterations (BAP1, p16/CDKN2A, NF2, LATS2, SETD2, DDX3X). After surgery and chemotherapy, she was doing well two months later with no new lesions. The authors concluded that this variant should be considered for abdominal or pelvic masses with clear cell features, and that its course and prognosis remain unclear.

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 who presented with abdominal and right flank pain (SUNY Upstate Medical University, Syracuse, NY, USA; surgery in February 2018)
• Exposure: the article states the patient had no clinical history of asbestos exposure; no fiber type or exposure measurement is reported
• Main results:
  • CT found a 27.2 cm abdominal mass and a separate 5.5 cm lesion in the liver
  • Two abdominal lesions seen on a January 2014 CT (one first noted in 2010) had been thought likely to be hemangiomas. They were judged, looking back, to be the current mass, which had grown over several years.
  • Based on the tissue staining pattern and the appearance of the cells, the tumor was diagnosed as epithelioid mesothelioma, clear cell variant
  • Molecular testing found a VHL gene alteration involving exon 2, which the authors describe as a novel genetic finding in malignant mesothelioma
  • On the clinical PCR panel, none of the six common mesothelioma-associated alterations listed (BAP1, p16/CDKN2A, NF2, LATS2, SETD2, DDX3X) were positive
  • The patient had wide excision of the mesenteric mass, partial liver resection and chemotherapy. Two months later she was doing well with no evidence of new lesions.
• The authors' conclusion: The authors concluded that this clear cell variant of peritoneal epithelioid mesothelioma should always be considered in patients with an abdominal or pelvic mass with clear cell features. Because it is so rare, its clinical course, prognosis, pathogenesis and molecular profile remain unclear.
• Limitations the authors state:
  • The authors state it is unclear whether the clear cell appearance of the tumor is related to the VHL gene mutation; further genome-wide studies are needed
  • The authors state that, given the rarity of the tumor, its clinical course, prognosis, pathogenesis and molecular profile remain unclear

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: Epithelioid, Mesothelioma, Peritoneum, Asbestos Exposure, Eosinophilic, Immunohistochemistry, Malignant Mesothelioma, Prognosis.

Related studies

• Primary pleural epithelioid mesothelioma of clear cell type: a case report and review of current literature — C. Gkogkou, K. Samitas, et al. (2011)
• Hypoxia Inducible Factor-1α Inhibition in Von Hippel Lindau-mutant Malignant Pleural Mesothelioma Cells — T. Shukuya, J. Oyanagi, et al. (2020)
• Establishment and mutation analysis of a novel malignant peritoneal mesothelioma cell line, TU-MM-1, using whole genome sequencing — N. Oumi, H. Itamochi, et al. (2016)
• Primary peritoneal clear cell carcinoma versus ovarian carcinoma versus malignant transformation of endometriosis: a vexing issue — L. Insabato, V. Natella, et al. (2015)
• High frequency of inactivating mutations in the neurofibromatosis type 2 gene (NF2) in primary malignant mesotheliomas — A.B. Bianchi, S.I. Mitsunaga, et al. (1995)
• Driver Gene and Novel Mutations in Asbestos-Exposed Lung Adenocarcinoma and Malignant Mesothelioma Detected by Exome Sequencing — S. Mäki-Nevala, V.K. Sarhadi, et al. (2016)

Browse more research in Human Pathology, or return to medical research.