Heart Tumor

What is a heart tumor?

A heart tumor, or cardiac tumor, is a rare, abnormal growth that develops in the heart. Heart tumors can occur in any location, such as on the valves, within the heart muscle, inside a chamber, or around the heart. Most heart tumors in children are benign, meaning they are non-cancerous, and unlikely to spread to other organs. However, even benign tumors can be life threatening if they cause problems with blood circulation or cause an abnormal heart rhythm.    

What is the difference between a tumor and a mass?

A cardiac mass is a general description of a lump of tissue found in the heart. The mass could be caused by a tumor, or something else that is not a tumor. A tumor is specifically caused by an abnormal growth of cells. A mass that is not a tumor could be from a variety of causes, such as a malformed structure, or pooling of blood cells within a section of the heart.

Fibroma Heart Tumor myxomaHeart Tumor Rhabdomyomas

Are there different types of heart tumors?

There are many types of heart tumors in children. The most common are rhabdomyomas and fibromas. Most are benign, meaning they are not cancer. In rare cases (fewer than 1 percent), heart tumors are cancerous. The table below describes the percentages of each tumor type seen at Boston Children's. 

Name of heart tumor

Percent of all tumors









Intrapericardial teratoma






Malignant (cancerous)

fewer than 1%



What are the symptoms of a heart tumor?

Most children with heart tumors have no symptoms. But for those who do, the heart tumor symptoms often imitate those of other heart conditions. This can make them a challenge to diagnose. Depending on the tumor location, size, and growth rate, children may have:

  • heart failure
  • heart murmurs
  • palpitations, rapid heart rate, or arrhythmia 
  • shortness of breath or difficulty breathing
  • breathing problems when changing positions or lying flat
  • dizziness, lightheadedness, or fainting
  • chest pain or chest tightness

What causes heart tumors?

Causes of heart tumors vary. For the most part, heart tumors are believed to be the result of abnormal growth of heart tissue cells. A small percentage of tumors are genetically inherited, which can be found with genetic testing. In most cases, tumors develop without any family history.

My child was diagnosed with a heart tumor. What questions should I ask my doctor?

Below are some key questions to ask your doctor:

  • Is there only one tumor in the heart, or more than one?
  • Is the tumor inside the heart or around the heart?
  • Is the tumor causing any problems with blood flow?
  • Do you know what type of tumor it is?
  • What is the chance the tumor is cancerous?
  • Would a cardiac MRI or CT help evaluate the tumor?
  • Should my child have additional testing to look for a heart rhythm abnormality?
  • Is there a possibility my child has a genetic abnormality that is associated with this type of tumor? If so, should my child see a specialist in genetics?
  • What is the recommended treatment for the tumor? Could it be biopsied or removed?
  • What is the long-term outlook for my child?

How we care for heart tumors

The Boston Children’s Hospital Heart Tumor Program has one of the most accomplished teams of cardiologists and cardiac surgeons in the field of managing cardiac tumors in children. Our expertise in diagnosis and treatment leads to better surgical interventions and arrhythmia management for the best possible outcomes.