Pericardial mesothelioma presenting as left atrial thrombus in a patient with mitral stenosis

Our plain-English summary of Pericardial mesothelioma presenting as left atrial thrombus in a patient with mitral stenosis, by Y. Miyamoto, S. Nakano, Y. Shimazaki, et al (Cardiovascular Surgery, 1996).

The study

• Authors: Y. Miyamoto, S. Nakano, Y. Shimazaki, H. Matsuda, H. Fukuda
• Journal: Cardiovascular Surgery
• Published: 1996;4(1):51-2
• Type of article: Case report
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Primary pericardial mesothelioma is rare and remains a diagnostic and therapeutic challenge. Pericardial mesothelioma usually occurs independently of intracardiac lesions and infiltrates adjacent tissues superficially. An extremely rare case of malignant pericardial mesothelioma complicated by prior mitral valve surgery is reported. The tumour invaded the left atrium and mimicked a thrombus.

In plain English

This article was a case report about one patient: a 56-year-old woman in Japan with a primary malignant mesothelioma of the pericardium, the sac around the heart. One year earlier she had had heart surgery on her mitral valve, including removal of a clot from the left atrium. When a large mass reappeared in the left atrium, it was treated as a new clot. A 350 g mass was removed during valve replacement and was not sent for pathological examination. The mass returned by the 19th day after surgery despite strict anticoagulant treatment. A further operation on the 49th day found tissue encasing the heart and great vessels, and she died 5 days later. Autopsy and microscopy showed malignant mesothelioma that had invaded the heart, with the pleura and peritoneum intact. The authors hypothesized that the tumour developed from the remaining pericardium after the first surgery. They concluded that the mass should have been examined histologically, and that diagnosis before death would then have been possible. The article did not report any asbestos exposure.

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
• Who was studied: One 56-year-old woman with mitral stenosis, treated at Osaka University Medical School, Japan, who had undergone open mitral commissurotomy and left atrial thrombectomy 1 year earlier
• Exposure: The article did not report asbestos or any other exposure history for the patient
• Main results:
  • The patient had undergone open mitral commissurotomy and left atrial thrombectomy 1 year before admission
  • During mitral valve replacement, a large soft mass weighing 350 g was removed from the left atrium. It was thought to be a recurrent thrombus and was not submitted for pathological examination
  • The mass recurred in the left atrium by the 19th postoperative day despite strict anticoagulant therapy
  • Because the mass enlarged, surgery was performed again on the 49th postoperative day
  • The patient died 5 days after the last surgery
  • At autopsy the tumour ranged from 1 cm thick over the right ventricle to 4 cm over the great vessels, and had invaded the right atrial wall, the right ventricle muscle and the left atrium
  • The exact origin of the tumour could not be identified at autopsy. The pleura and peritoneum were intact
  • No tumour was found in the liver, lungs, intestines or bones
• The authors' conclusion: The authors hypothesized that the mesothelioma developed from the remaining pericardium after the first surgery and then invaded the left atrium. They stated that examining the mass under the microscope after the valve replacement would have made diagnosis before death possible and could have led to chemotherapy, and that the thrombus-like mass should have been studied histologically

Topics

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

Medical terms in this study, explained in our Lexicon: Pericardial Mesothelioma.

Related studies

• Primary pericardial mesothelioma in a 19-year-old presenting as pericarditis — M.O. Kayatta, S.P. Dineen, et al. (2013)
• Pericardial mesothelioma presenting as a suspected ST-elevation myocardial infarction — A.S. Barroso, S. Leite, et al. (2017)
• Unexpected malignant pericardial mesothelioma presenting as pericardial constriction — M. Oc, B. Oc, et al. (2012)
• Pericardial malignant mesothelioma: a latent complication of radiotherapy? — G.R. Small, M. Nicolson, et al. (2008)
• A second case of pericardial mesothelioma mimicking systemic lupus erythematosus in the literature in over 30 years: a case report — C. Mensi, A. Romano, et al. (2017)
• Recurrent pericardial effusion with pericardial amyloid deposition: a case report and literature review — H. Itagaki, T. Yamamoto, et al. (2020)

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