This may be a confusing medical description as it suggests that the cancer started, and is confined to the heart. The cancer will have begun in other parts of the body and spread to the heart. Where the cancer begins near to the heart, the heart may become involved.
The rare condition of primary cardiac tumor is cancer that arises in the heart. Cancerous tumors that begin in the heart are most often sarcomas, a type of cancer that originates in the soft tissues of the body. Most often, heart tumors are noncancerous (benign). Heart cancer is extremely rare. For example, one study reviewed more than 12,000 autopsies and found only seven cases of primary cardiac tumor.