Though primary cardiac cancer is very rare, cardiac mets may not be as rare as we thought!
Interestingly, a 1954 case review from Circulation by Drs. Young and Goldman found that out of 586 patients who had died of tumor and underwent autopsy (not counting leukemia, where myocardial infiltration was found in almost half of cases!) 19.1% had cardiac involvement. The authors noted that their large percentage may have been related to seeing many cases of bronchogenic ca, melanoma, lymphoma, pancreatic cancer, and esophageal cancer. Indeed, the most common primary tumor associated with cardiac mets by proportion was melanoma (64.7% of cases), but cases of metastatic lung cancer and lymphoma also had a high proportion of cardiac involvement.
In another, more recent, case series (2007), cardiac mets were found in 14% of autopsies where the patient had metastatic cancer. “About two thirds of all cardiac metastases involved the pericardium (69.4%), one third the epicardium (34.2%) or the myocardium (31.8%) and only 5% the endocardium.” (adds up to more than 100 because some involve multiple areas of the heart. The authors additionally found that the primary malignancy associated with highest rate of cardiac metastases (to all cardiac structures) was pleural mesothelioma (48.4%) followed by melanoma (27.8%) but that other malignancies metastasized to cardiac structures as follows:
- Mets involving Pericardium – mesothelioma, lung, ovary, stomach, prostate
- Mets involving Epicardium – melanoma, lung (squamous and bronchoalveolar)
- Mets involving Myocardium – melanoma, lymphomyeloproliferative maligs
- Mets involving Endocardium (most rare) – melanoma, kidney, liver (tumors often associated with endovascular spread)
Finally, it should be noted that as our ICU attendings emphasized this morning, when dealing with tamponade we should remember that it’s the intrapericardial pressure that drives decreased CO. Therefore, the mainstay of management is attempting to increase R sided intracardiac pressures by increasing preload (fluids, fluids, fluids) while decreasing the intrapericardial pressure by draining the effusion.