Cancer Health Center

Malignant pericardial effusions occur in up to 21% of cancer patients [1,2,3] and are frequently not suspected until clinical signs or symptoms of pericardial tamponade develop.[4] Two thirds of patients have subclinical pericardial effusions with no overt cardiovascular signs or symptoms.[5,6] One half of cases of pericardial effusion initially present with symptoms of cardiac tamponade.[7] In one half of cases, pericardial effusion is the first sign of malignant disease.[8] Symptoms of pericardial effusion are often attributed to the underlying cancer. Dyspnea, fatigue, or asthenia may be the initial symptoms.[9] Symptomatic pericardial effusions are often a preterminal event; however, significant symptom palliation can be achieved by prompt diagnosis and management.

Of patients with malignant pericardial effusions, 50% will have concomitant pleural effusions, and one third will have pulmonary parenchymal disease.[4]

One third of patients with pericardial metastases will eventually die from pericardial tamponade.[4] Pericardial involvement contributed to the cause of death in 85% of patients in a series reported in 1962 but in only 46% of patients in a recent study.[10] Improvements in diagnostic and therapeutic options account for the decrease in mortality over the past 40 years.

Incidence and Prevalence

Malignant pericardial effusion occurs in up to 21% of autopsy series in patients with common malignancies.[4,7] Of patients with lung cancer, 33% have pericardial metastases at autopsy, and one third of cases of pericardial metastases are caused by lung cancer. Breast cancer causes 25% of pericardial effusions, and about 25% of patients with breast cancer have pericardial effusion. Hematological malignancies (leukemia, Hodgkin disease, non-Hodgkin lymphoma) cause 15% of cases of malignant pericardial effusions.[11]

A retrospective review of 23,592 effusions over a 24-year period revealed 65 malignant effusions (17%) out of 375 pericardial effusions. Lung cancer was the most common cancer found among the malignant pericardial effusions in males, and breast cancer was the most common in females. In 43% of cases, pericardial effusion was the first detected sign of cancer. Of patients diagnosed with malignant pericardial effusions, 86% died within 1 year of diagnosis, with nearly one third dying within the first month.[8]

In a study of 31 patients with both cancer and pericardial effusions, malignant pericardial effusion accounted for 58% of the effusions, 32% were caused by benign idiopathic pericarditis, and radiation pericarditis caused 10% of cases.[11,12]

Pathophysiology

Malignant involvement of the pericardium is the most common reason for development of pericardial effusions, which result from blockage of venous and lymphatic circulation of pericardial fluid. Such blockage may be caused by primary malignancy of the pericardium, as with pericardial mesothelioma, or by tumors arising in the myocardium, including angiosarcoma, rhabdomyosarcoma, and malignant fibrous histiocytosis. Malignancies can also involve the pericardium through direct extension from carcinomas of the lung or esophagus, thymoma, or lymphoma.[9] Lymphatic or hematogenous metastasis to the pericardium occurs most commonly with carcinomas of the breast and lung, leukemia, lymphoma, and melanoma. Primary tumors of the pleura or pericardium have recently been termed primary intrathoracic malignant effusions.[13]