- In developed countries, malignancy is the leading cause of pericardial effusion, primarily due to the direct invasion or metastatic spread of cancer cells to the pericardium.
- This often leads to an exudative effusion with malignant cells present in the pericardial fluid.
- While infectious causes such as tuberculosis dominate in developing regions, malignancy-related effusions are more prevalent in industrialized nations due to higher cancer incidence and survival rates.
- Early recognition of malignant pericardial effusion is crucial, as it may indicate advanced disease and necessitates targeted oncologic and symptomatic treatment.

Reference: Davidson’s Principles and Practice of Medicine, 23rd Edition, Chapter: Disorders of the Pericardium, Page 759.