3. Discussion
3.1 Clinical manifestations of PPM
The incidence of PPM is extremely low, with multiple occurrences in
middle-aged men and an unknown etiology 3.PPM has no
characteristic clinical manifestations, and the main symptoms are
dyspnea, chest tightness, chest pain, cough, sputum, fever, and night
sweats. The main signs of PPM include enlargement of the heart, distant
heart sounds, pericardial percussion, and various signs of systemic
congestion. PPM is often misdiagnosed as tuberculous pericarditis and
constrictive pericarditis4. There was no history of
asbestos exposure in this case. The patient had no obvious abnormalities
in liver function 1 year ago, and long-term alcohol consumption led to
alcoholic cirrhosis. Pericardial disease led to right heart failure,
which accelerated the process of liver failure.
3.2 Imaging diagnosis of PPM
Echocardiography is the most frequently used method of evaluation of PPM
and can identify the location and morphology of a tumor and assess the
effect of the tumor on cardiac hemodynamics and determine the
hypocardial function5. However, PPM lacks
characteristic echocardiographic imaging changes, and its diagnosis is
influenced by the experience and subjectivity of the ultrasound
physician. Cardiac CT is better than echocardiography for observing
pericardial changes, and enhanced scans can determine the condition of
the large blood vessels of the heart. Studies have shown that
low-density areas suddenly appear within the thickened pericardium,
which may be associated with necrosis inside the tumor6. In the current case, cardiac CT showed marked
pericardial diffuse thickening with nodular changes and decreased
density of the heart chambers and large blood vessels, consistent with
these studies. CMR can identify the surrounding soft tissue invasion and
allows a reliable judgment on the nature of the pericardial tumor, the
degree of myocardial infiltration, and the location7.
PET-CT provides detailed molecular information about the function and
metabolism of lesions, allowing for the early detection of pericardial
tumors, and can determine benign and malignant nature and
metastasis8. In summary, imaging data is conservative
regarding the diagnosis of PPM, and generally prioritizes pericarditis
in terms of imaging performance. Even with optimal cardiac CMR and
PET-CT, there are often no characteristic changes and lesions are rarely
considered as pericardial tumors, which is the main cause of
preoperative misdiagnosis or missed diagnosis.
3.3 Pathological results and immunohistochemical analysis of PPM
Postoperative pathology combined with immunohistochemical analysis is
the gold standard for diagnosis of PPM9.The anatomical
typing of PPM includes diffuse and focal types, with diffuse types being
more common. Histological classifications are epithelial, sarcoma, and
bipolar, with epithelial being the most common10.
Currently, combined immunohistochemistry showing negative expression of
CKp (AE1/AE3), CK5/6, CK18/19, EMA, MC, wave protein (vimentin),
calretinin, carcinoembryonic antigen (CEA), and thyroid transcription
factor is recommended for PPM2,9-14.The
immunohistochemical expression signature of PPM is mostly the
permutation and combination of the above antibodies. This case also
confirmed the results of the above pathological typing and
immunohistochemical analysis, consistent with the diagnosis of PPM.
3.4 Treatment and prognosis of PPM
Surgery is the main treatment for primary cardiac malignancy, which not
only removes tumor tissue and obtains material for the pathological
diagnosis, but also relieves clinical symptoms caused by tumor
blockage15. Because PPM is rare, a unified treatment
specification has not been determined clinically. However, in PPM
treatment, surgery is critical for solving pericardial thickening,
adhesions, and restoring cardiac contractile
function16. When the patient has life-threatening
comorbidities, surgery can relieve pericardial compression, prolong
survival time, and improve quality of life. In the current case, the
surgical effect was remarkable, successfully relieving the pericardium
from extensive thickening and adhesions. The patient was alive at
follow-up at 3 months postoperatively. Postoperative combination of
chemotherapy and radiation therapy may improve prognosis, but long-term
efficacy remains poor. However, chemotherapy after cardiac malignancy
resection should be beneficial 17. PPM treatment is
trending towards a combination of surgery, radiotherapy, chemotherapy,
and other comprehensive treatment measures.
PPM has extremely low incidence, atypical clinical manifestations,
difficult early diagnosis, and poor prognosis. Nevertheless, clinicians
should extend their understanding of the disease and strive to achieve
early diagnosis, early intervention, and improve prognosis to enhance
patient survival.
ACKNOWLEDGMENTS
We thank H. Nikki March, PhD, from Liwen Bianji (Edanz)
(www.liwenbianji.cn/), for editing the English text of a draft of this
manuscript.
CONFLICT OF INTERESTS
The authors declare no conflict of interest.
ETHICS AND LEGAL
IRB approval, clinical trial statement, and registration details are
N/A. Informed consent was obtained from both the patient and their legal
guardian for this case report.
AUTHOR CONTRIBUTIONS
Qiansu chen – Concept/Design, critical review of draft, case analysis,
and interpretation.
Nailin Gong and Lude Liu have equal contributions to this article. –
Case analysis and interpretation, report drafting, and revisions.