About 10% of all patients with advanced-stage cancer develop cardiac metastasis, with the majority (about 75%) involving the epicardium and/or pericardium.^1,2 Metastases usually involve the pericardium by either direct extension or lymphatic spread. Lymphatic drainage of the heart usually flows from endocardium to epicardium. About two-thirds of metastases to the heart involve the pericardium, which can include the visceral pericardium (epicardium) or parietal pericardium.³

Metastatic tumors to the pericardium are most commonly carcinoma from the lung or breast. Other primary sites include the gastrointestinal tract, skin (melanoma) pancreas, kidney, thyroid, urinary bladder, ovary, endometrium, and thymus. Other nonepithelial metastases include lymphoma, angiosarcoma, and other metastatic sarcomas.^{1,2,3,4,5,6,7,8,9}

The most common carcinoma to metastasize to the pericardium is non-small cell lung carcinomas, in both men and women. Adenocarcinomas form 75% of this group and small cell carcinoma, 12%.¹⁰ In women, breast carcinoma is the second most common neoplasm to involve the pericardium, with breast and lung carcinomas collectively accounting for >90% of pericardial metastases.⁵ In a series of pericardial metastases with postive fluid cytology, the most common tumor was lung cancer (52%), followed by breast cancer (13%), carcinoma of the esophagus (8%), non-Hodgkin lymphoma (8%), leukemia (5%) sarcoma (5%), and one each of thymoma, melanoma, carcinoma of the colon, testicular germ cell tumor, and squamous carcinoma of unknown origin.¹¹