Metastatic primary peritoneal malignant mesothelioma mimicking primary diffuse gastric carcinoma: a rare encounter in gastric biopsy

Our plain-English summary of Metastatic primary peritoneal malignant mesothelioma mimicking primary diffuse gastric carcinoma: a rare encounter in gastric biopsy, by Y. Yang, D. Gunawardane, D. Moffat, et al (Pathology, 2017).

The study

• Authors: Y. Yang, D. Gunawardane, D. Moffat, C. Carter
• Journal: Pathology
• Published: 2017;49(3):317-319
• Type of article: Case report, Letter
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This letter is a case report from SA Pathology, Adelaide, Australia, about one 62-year-old man. Abdominal fluid (ascites) was noticed during a routine heart scan in June 2016. CT scans showed thickening of the lower stomach and abdominal lining (peritoneum) and omental nodules, suspicious for spread of stomach cancer. The chest CT showed a small pleural effusion but no pleural plaques. A biopsy of stomach erosions was first read as an early stomach adenocarcinoma, without special stains. Fluid drawn from the abdomen then looked suspicious for mesothelioma. Stains on the stomach biopsy, a peritoneal biopsy and the fluid were positive for mesothelial and negative for adenocarcinoma markers. The diagnosis became metastatic diffuse primary epithelioid peritoneal mesothelioma. A history of asbestos exposure was confirmed on further enquiry; the letter does not describe the fiber type or how the exposure happened. The patient was on palliative chemotherapy. The authors attributed the first misreading largely to the very small amount of tumour in the biopsy, its gland-forming look mimicking adenocarcinoma, and compatible scans. They said the case highlights how hard mesothelioma is to recognise in an unusual site.

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 (letter to the editor describing a single patient)
• Who was studied: one 62-year-old man, seen in 2016; authors at SA Pathology, Adelaide, Australia
• Exposure: a history of asbestos exposure, confirmed on further enquiry; no fiber type, job, product or dose is described
• Main results:
  • CT findings (gastric antral thickening, ascites, peritoneal thickening, omental nodules) were suspicious for metastatic gastric carcinoma
  • Chest CT showed a small pleural effusion and no pleural plaques or calcifications
  • The gastric biopsy was initially read as consistent with intramucosal adenocarcinoma; immunohistochemistry was not done at that time
  • Cytology of the ascitic fluid was suspicious for mesothelioma
  • Tumour cells in the gastric biopsy were strongly positive for the mesothelioma markers calretinin and CK5/6 and negative for the adenocarcinoma markers B72.3 and CEA
  • The final diagnosis was metastatic diffuse primary epithelioid peritoneal mesothelioma
  • The patient was receiving palliative chemotherapy at the time of the report
  • The authors attributed the misinterpretation of the gastric biopsy largely to the very limited quantity of tumour in the small biopsy sample
  • The authors also attributed the misinterpretation to the tumour's gland-forming nature mimicking adenocarcinoma and to compatible imaging findings
• The authors' conclusion: The authors concluded that the case highlights the difficulty of recognising mesothelioma and the high vigilance needed when it appears in an unusual site, such as a gastric biopsy

Topics

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

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Carcinoma, Biopsy.

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