Ultrasonic manifestations of diffuse pericardial mesothelioma masquerading as pericardial effusion: a case report

Our plain-English summary of Ultrasonic manifestations of diffuse pericardial mesothelioma masquerading as pericardial effusion: a case report, by S. Zhu, Y. Zhou (Frontiers in Oncology, 2026).

The study

• Authors: S. Zhu, Y. Zhou
• Journal: Frontiers in Oncology
• Published: 2026;16:1921935
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Primary pericardial mesothelioma (PPM) is an exceedingly rare, highly invasive cardiac neoplasm with insidious onset and non-specific clinical symptoms. Due to the lack of typical early manifestations and effective routine diagnostic methods, PPM is often misdiagnosed and missed, resulting in delayed treatment and poor prognosis.

Case Presentation: A 42-year-old male presented with 6 months of recurrent chest tightness and pain, worsening over 2 months, and two prior admissions for unexplained pericardial effusion. On admission, he had tachycardia, distant heart sounds, bilateral lower extremity edema, and a 3×2 cm hard, fixed left supraclavicular lymph node. Imaging confirmed pericardial effusion with abnormal pericardial lesions. Ultrasound-guided pericardiocentesis yielded only a small amount of red jelly-like material, with cytology suggesting epithelioid neoplastic cells. Supraclavicular lymph node biopsy confirmed metastatic malignant mesothelioma. Nivolumab immunotherapy showed no improvement. Pericardial tumor resection revealed diffuse, fish-flesh-like tumor invading the myocardium and great vessels. Final pathology confirmed epithelioid-type PPM.

Conclusion: Patients with recurrent unexplained pericardial effusion and atypical sonographic features, such as flocculent echoes and irregular pericardial thickening, should raise suspicion for PPM. Early recognition of these signs and timely pathological confirmation are critical to avoid diagnostic delays and may improve outcomes.

Copyright © 2026 Zhu and Zhou.

In plain English

This case report described a 42-year-old man in China with six months of recurring chest tightness and pain who had twice been hospitalized for fluid around the heart (pericardial effusion). He denied prior asbestos exposure. Heart ultrasound showed dark, fluid-like areas around the heart with flocculent bright specks, and pericardial lesions up to 29 mm thick. No discrete solid mass was seen at first, and doctors initially suspected inflammatory pericarditis. Needle drainage drew almost no fluid, only red gelatinous material containing epithelioid tumor cells. A biopsy of a lymph node above the left collarbone showed spread of malignant mesothelioma. His symptoms worsened after he started nivolumab. At surgery, tumor covered the entire pericardium and invaded the heart muscle and great vessels. Pathology confirmed epithelioid malignant pericardial mesothelioma. He died of sudden heart failure on the third day after surgery. The authors concluded that recurrent unexplained pericardial effusion with atypical ultrasound features, such as irregular pericardial thickening or flocculent echoes, should raise early suspicion of this cancer. They noted that a single case cannot be generalized.

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 a table comparing previously published cases
• Who was studied: one 42-year-old man treated at the Affiliated Jinhua Hospital, Zhejiang University School of Medicine, Jinhua, China
• Exposure: No asbestos exposure was reported; the patient denied prior asbestos exposure
• Main results:
  • Transthoracic echocardiography showed anechoic (dark, fluid-like) areas in the pericardium with flocculent hyperechoic (bright) specks
  • On ultrasound, the pericardial lesion next to the front wall of the right ventricle was 29 mm thick and the lesion beside the back wall of the left ventricle measured 25 mm
  • At initial presentation, imaging showed no discrete solid pericardial mass
  • Ultrasound-guided pericardiocentesis drew almost no fluid. Cytology of the small amount of red gelatinous material collected found epithelioid neoplastic cells
  • The authors noted that the typical effusion was absent in this case and jelly-like material was present instead
  • Core needle biopsy of the left supraclavicular lymph node confirmed metastasis of malignant mesothelioma
  • Nivolumab was given at 200 mg intravenously every 2 weeks. Ten days after the first cycle, chest distress and shortness of breath worsened
  • At surgery, the tumor involved the entire pericardium and infiltrated the myocardium and surrounding great vessels. Final pathology was epithelioid malignant pericardial mesothelioma
  • The patient died of sudden heart failure on the third postoperative day
• The authors' conclusion: The authors concluded that recurrent unexplained pericardial effusion combined with atypical ultrasound features, such as irregular pericardial thickening or flocculent echoes, should arouse early clinical suspicion of primary malignant pericardial mesothelioma
• Limitations the authors state:
  • As a single-case study, its conclusions cannot be generalized to broader patient populations
  • Clinical observation was limited because the patient died soon after surgery

Topics

Medical terms in this study, explained in our Lexicon: Pericardial Mesothelioma, Pericardial Effusion, Neoplasm, Prognosis, Bilateral, Pericardial, Ultrasound, Pericardiocentesis.

Related studies

• Pericardial mesothelioma masquerading as a benign pericardial effusion — N.L. Coplan, A.J. Kennish, et al. (1984)
• Diffuse intrapulmonary malignant mesothelioma masquerading as interstitial lung disease: a distinctive variant of mesothelioma — B.T. Larsen, J.R. Klein, et al. (2013)
• Cardiac tamponade as the initial manifestation of primary pericardial mesothelioma — M. Stein, A. Neuman, et al. (1995)
• Unusual region for pericardial malignant mesothelioma: cutaneous manifestation in a Turkish woman — M. Günday, H. Erinanç, et al. (2013)
• Sudden death as the initial manifestation of diffuse pleural mesothelioma — J.T. Lie (1989)
• Multi-sensor datasets of ultrasonic and mmWave reflected signals for material classification — M.H. Sadiq, S.A. Abdulkareem, et al. (2026)

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