Case Report: Primary malignant mesothelioma of the left atrium easily misdiagnosed as myxoma

Our plain-English summary of Case Report: Primary malignant mesothelioma of the left atrium easily misdiagnosed as myxoma, by S. Luo, Y. Li, J. Li, et al (Frontiers in Cardiovascular Medicine, 2024).

The study

• Authors: S. Luo, Y. Li, J. Li, J. Zeng, J. Wang
• Journal: Frontiers in Cardiovascular Medicine
• Published: 2024;11:1398311
• Type of article: Case report
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Malignant mesothelioma (MM) is a rare and aggressive tumor that is found in the pleura and peritoneum. A few cases of MM in the pericardium and tunica vaginalis testis have been reported. Moreover, primary occurrence in the atrium is extremely rare. The visual appearance of this tumor is similar to that of a common atrial myxoma, which makes it challenging for clinicians and radiologists to diagnose and treat this disease.

Case Demonstration: An 18-year-old woman presented with symptoms of chest pain, shortness of breath, cough, and expectoration for 7 days. Echocardiography was performed on the patient, which revealed an atrial mass. Myxoma was one of the differential diagnoses. The tumor was an elliptical mass with tips, and the cut surface was jelly-like, similar to myxoma. After surgery, a pathologic examination of the biopsied tumor confirmed epithelial-type MM. During postoperative follow-up, no recurrence of the tumor was observed.

Conclusions: MM originating in the atrium is considered to be extremely rare. Consequently, clinicians can easily misdiagnose atrial MM as a myxoma. Moreover, to confirm the diagnosis, histopathologic biopsy, histomorphological characterization, immunohistochemistry, and molecular genetic testing are required. Therefore, clinical diagnosis and treatment of MM are challenging.

© 2024 Luo, Li, Li, Zeng and Wang.

In plain English

This article was a case report from the Department of Pathology at the Affiliated Hospital of Zunyi Medical University in China. It described one 18-year-old woman who came to hospital with chest pain and shortness of breath after activity, along with a cough for 7 days. The authors reported that she had no history of asbestos exposure or tumors. An ultrasound of the heart showed a mass in the left atrium, and left atrial myxoma (a common benign heart tumor) was considered as a possible diagnosis. Surgeons removed the mass, which was jelly-like and measured 5 cm by 5 cm by 4 cm. Microscope and staining tests led to a diagnosis of epithelioid malignant mesothelioma of the left atrium, confined to the atrium without pleural involvement. The patient did not receive radiotherapy after surgery, and no recurrence was seen on a repeat heart ultrasound after 3 months. The authors concluded that clinicians can easily misdiagnose atrial malignant mesothelioma as a myxoma.

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), with discussion of the published literature
• Who was studied: One 18-year-old woman diagnosed at the authors' hospital (Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China), who presented with chest pain and shortness of breath after activity, plus cough and expectoration for 7 days
• Exposure: The authors reported that the patient had no history of asbestos exposure; no fiber type or occupational exposure was described
• Main results:
  • Echocardiography of the patient showed echo groups (a mass) in the left atrium, and left atrial myxoma was considered as a differential diagnosis
  • The surgically removed tumor was a grayish-white, jelly-like mass measuring 5 cm by 5 cm by 4 cm
  • On immunohistochemistry, the patient's tumor was positive for calretinin, CK5/6, CK, D2-40, WT-1 and vimentin, and negative for TTF-1, napsin A, CEA, CK7, CD31, CD34 and other markers
  • The Ki-67 positive index of the patient's tumor was approximately 40 percent
  • The pathologic diagnosis was left atrial epithelioid malignant mesothelioma, confined to the left atrium without pleural involvement
  • The patient did not receive postoperative radiotherapy, and no recurrence was seen on repeat echocardiography after 3 months
• The authors' conclusion: The authors concluded that malignant mesothelioma arising in the atrium is extremely rare and can easily be misdiagnosed as a myxoma. They stated that confirming the diagnosis requires histopathology, immunohistochemistry and molecular testing.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Pleura, Peritoneum, Pericardium, Tunica Vaginalis, Biopsy, Immunohistochemistry.

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