A tumor, an abnormal growth, can develop anywhere in the body. That includes the heart. Most tumors in the heart, or heart valves, are benign (non-cancerous). Yet they’re treated by doctors as seriously as a malignant (cancerous) tumor because even the smallest abnormality can upset how the heart functions.
Still, heart cancer is rare. Here’s why: Cancer’s spread depends on continuous division of cancerous cells, but cells in the heart rarely divide. (Researchers at UCLA, in 2014, were the first to actually measure the division of heart muscle cells.) But a cardiac tumor can cause severe health problems, even death.
Types of Cardiac Tumor
Cardiac tumors are classified as either primary or secondary.
Primary: These tumors, highly unusual, originate in the heart’s tissue. They account for less than 1 percent of all cardiac tumors, according the National Institutes of Health.
Secondary: A tumor that originates in another part of the body and moves into the heart. Secondary tumors – which can start in the kidneys, stomach, breasts, lungs, colon or liver – are 20 to 40 times more common than primary tumors. They’re also known as metastatic cancers.
All three layers of the heart and the sac that surrounds it are susceptible to tumors.
Epicardium: A thin outer layer of connective tissue and fat that provides additional support to the sac (pericardium) around the heart.
Myocardium: The heart’s muscle tissue.
Endocardium: A thin inner lining that covers the interior chambers and the heart valves.
Pericardium: A two-layered membrane encasing the heart, with the inner layer attached to the epicardium.
Symptoms
A patient might not notice a cardiac tumor because it sometimes has no obvious symptoms. A doctor might not notice it, either, because a cardiac tumor can resemble other heart diseases.
A tumor is sometimes discovered when a doctor prescribes an echocardiogram for a different reason.
Typical signs of various benign cardiac tumors:
Myoxma
This is the most common type of primary cardiac tumor, usually developed in the left atrium.
- Chest pain or tightness.
- Shortness of breath during activity.
- Dizziness.
- Fainting.
- Difficulty breathing when laying down or asleep.
- Embolisms caused by fragments of the tumor that reach the bloodstream, producing clots or blockages.
- Blood flow blocked at the opening of a heart valve.
- Heart palpitations.
Rhabdomyoma
A tumor in the myocardium or endocardium, responsible for about 20 percent of tumors that originate in the heart.
Few apparent signs or symptoms:
- Shortness of breath.
- Fatigue.
- Confusion.
- Irregular heartbeat.
- Heart failure (bluish skin, fluid in lungs).
Fibroma
Tumors on the heart valves, perhaps caused by inflammation, in the myocardium or endocardium. These slow-developing tumors are rare, most often found in children.
In more than one-third of cases, no signs or symptoms are detected.
When they are:
- Dizziness.
- Fainting.
- Bluish skin.
- Severe arrhythmias.
- Blood flow blockages.
- Heart failure.
Malignant heart tumors
Sarcomas:
- Angiosarcomas (most common).
- Rhabdomyosarcomas.
- Liposacromas.
- Fibrosarcomas.
- Osteosarcomas.
- Leiomyosarcomas.
Primary Lymphoma
Extremely rare, accounting for about 1 percent of primary cardiac tumors.
Pericardial Mesothelioma
A rare form of mesothelioma, responsible for about 1 percent of known diagnosed mesotheliomas.
Causes
Medical experts generally attribute cardiac tumors to abnormal cell growth, but generic cancer risks still apply:
- Tobacco use.
- Overexposure to the sun.
- Radiation.
- Family history.
Treatment
If you have a benign (myoxma) cardiac tumor, your doctor will likely recommend surgical removal. But surgery for other cardiac tumors, such as rhabomyomas and fibromas, has proved less reliable.
Treating a malignant cardiac tumor becomes more complex. Your doctor might prefer chemotherapy and radiotherapy to surgery because cancers extend into heart tissue.