Most heart tumors begin with myxomas, fibromas, rhabdomyomas, and hamartomas, although malignant sarcomas (such as angiosarcoma or cardiac sarcoma) have been known to occur. In a study of 12,487 autopsies performed in Hong Kong seven cardiac tumors were found, most of which were benign. According to Mayo Clinic: "At Mayo Clinic, on average only one case of heart cancer is seen each year." In a study conducted in the Hospital of the Medical University of Vienna 113 primary cardiac tumour cases were identified in a time period of 15 years with 11 being malignant. The mean survival in the latter group of patients was found to be 26.2 ± 9.8 months.
Primary malignant cardiac tumors (PMCTs) are even more rare. A study using the Surveillance, Epidemiology and End-Results (SEER) Cancer Registry from 1973–2011 found 551 case of PMCTs, with an incidence of 34 cases per million persons. The study also found that the incidence has doubled over the past 4 decades. The associated mortality was very high, with only 46% of patients alive after one year. Sarcomas and Mesotheliomas had the worst survival, while lymphomas had better survival. When compared with extracardiac tumors, PMCTs had worse survival.