What Is the Most Common Cardiac Tumor in Children?

Medically Reviewed on 4/6/2022
What is the most common cardiac tumor in children
Although rare, rhabdomyomas are the most common type of heart tumor in children.

A cardiac tumor is a growth that occurs in the heart. Heart tumors in children are uncommon, affecting just approximately one percent of newborns. Rhabdomyomas are the most common type of heart tumor in children

Rhabdomyomas account for more than 60 percent of pediatric cardiac tumors. A rhabdomyoma is a benign (noncancerous) tumor that forms in clusters in the heart.

  • Cardiac rhabdomyomas are most commonly found in the muscles of the left and right ventricles (the lower chambers of the heart). Tumors seldom grow in the interventricular septum (the wall between the ventricles) or the atria (the upper chamber of the heart).
  • Rhabdomyomas form before birth, most commonly during the third trimester of pregnancy. A tumor that gets large enough can obstruct blood flow through the heart.
  • Smaller tumors may not produce any symptoms at all. Rhabdomyomas often shrink on their own throughout a child's first few years.

Other cardiac tumors in children

Other cardiac tumors that are commonly found in children include:

  • Fibromas:
    • They are usually detected shortly after delivery.
    • Doctors plan surgery almost immediately because it is linked to arrhythmia (an irregular cardiac rhythm).
    • Arrhythmias are the most prevalent symptom of a cardiac tumor.
  • Teratomas:
    • They rarely shrink and usually necessitate surgery.

Other malignant (cancerous) heart tumors, such as rhabdomyosarcoma and fibrosarcoma, are extremely rare in children.

6 common signs and symptoms of cardiac rhabdomyomas in children

Rhabdomyoma can impair the heart's ability to pump blood. Cardiac, respiratory, and hemodynamic parameters may be affected depending on the location and size of the tumor.

Six signs and symptoms of cardiac rhabdomyomas in children include:

  1. Shortness of breath
  2. Arrhythmias (irregular heart rhythms)
  3. Heart murmur
  4. Heart failure
  5. Blue discoloration of the skin due to insufficient blood oxygenation
  6. Abnormal renal functions

A tumor can grow large enough to obstruct blood flow to the heart during embryonic development in rare situations. This can lead to a condition known as fetal hydrops.

  • Hydrops are regions where fluid accumulates (around the heart or other areas of the body).
  • Hydrops develops as a result of heart failure and are deadly in 50 percent of instances.
  • People may present with signs and symptoms that are suggestive of cerebral palsy, implying the likelihood of concomitant tuberous sclerosis.


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How are cardiac rhabdomyomas diagnosed in children?

The majority of children with rhabdomyoma (approximately 80 percent) have the genetic disease tuberous sclerosis complex (TSC).

  • TSC causes noncancerous tumors to develop in the heart, brain, kidneys, eyes, lungs, and skin. 
  • Other occurrences of rhabdomyoma are isolated, which means the etiology is unclear and the child does not have TSC.

When one or more masses are seen on a prenatal ultrasound within the fetus's heart, doctors make a prenatal diagnosis of rhabdomyoma. If your baby is diagnosed with rhabdomyoma or you have a family history of the disorder, you will almost certainly need additional testing to confirm the diagnosis and monitor your baby's development.

Some of these tests are as follows:

  • Ultrasound:
    • These tumors could be discovered by your doctor during a routine ultrasound. However, most of these tumors are not visible to clinicians until after 22 weeks of gestation.
    • If there is a known family history, specialists recommend that moms begin serial ultrasounds (at regular intervals) at about 20 to 22 weeks, even if no tumors are seen on the first ultrasound check.
    • Ultrasound technologists may usually focus on the heart, neurological system, and kidneys.
  • Fetal echocardiogram:
    • Doctors recommend pregnant women to have fetal echocardiography (heart ultrasound) to check their baby's heart.
    • If the pediatric cardiologist notices tumors on your baby's heart, rhabdomyomas are the most likely diagnosis because there will almost always be more than one tumor.
    • Assessing the number of tumors, their size and location, and their ability to obstruct blood flow and/or heart function is critical in establishing the likely result.
    • These tumors may cause arrhythmias (irregular heartbeats or a heart rate that is either too rapid or too slow) and interfere with the cardiac conduction system.
    • It is vital to keep an eye out for fetal arrhythmias to assist anticipate your baby's likely prognosis.
  • Fetal anatomy:
    • Doctors should conduct a thorough examination of the infant to rule out any additional birth abnormalities. Some of the more common abnormalities that may accompany TSC include cysts (fluid-filled tumors) in the kidneys and problems of development in the brain.

Are cardiac rhabdomyomas in children treatable?

Rhabdomyomas may diminish and vanish on their own throughout a child's first few years of life. If your kid has these tumors, doctors will constantly evaluate their heart and overall health during your pregnancy and after birth.

Children with rhabdomyomas are subjected to regular echocardiograms and electrocardiograms to assess blood flow and heart rhythms. If testing reveals any blockages or arrhythmias, pediatric cardiologists will advise you on the best treatment options.

  • If a cardiac rhabdomyoma prevents blood supply to the baby's heart before birth, doctors can reduce the tumor with medications.
  • Only in extremely rare situations do doctors perform surgery after birth to eliminate tumors.
  • Children with tuberous sclerosis must be closely monitored. The sort of treatment required is determined by the location of the tumors.

What is the outcome of children with cardiac rhabdomyomas?

People who have undergone surgery to remove rhabdomyomas have a prognosis ranging from fair to good.

  • However, people with cardiac rhabdomyomas are more at risk if the tumor does not shrink.
  • The morbidity of rhabdomyoma is mostly determined by its size, location, number of lesions, and accompanying malformations such as tuberous sclerosis. 
  • Cardiac rhabdomyomas have the potential to cause flow problems if they become large enough to obstruct the left ventricular outflow pathway.
  • Although the majority of rhabdomyomas are asymptomatic, some afflicted people develop symptoms during pregnancy.

Based on clinical and molecular evidence, a diagnosis of fetal cardiac rhabdomyoma should prompt a detailed examination of other fetal structures, such as the brain and renal parenchyma, for symptoms of tuberous sclerosis.

Can rhabdomyoma or tuberous sclerosis affect my pregnancy?

The presence of rhabdomyomas in your unborn child is unlikely to have any effect on your pregnancy.

  • Your infant will need to be monitored more closely for tumor growth.
  • If tumors develop out of proportion to your baby's size, they may interfere with your baby's heart function.
  • If your kid gets heart failure and nonimmune hydrops, you are more likely to experience difficulties as well.
  • Mothers of babies with nonimmune hydrops are at risk of mirror syndrome. This syndrome creates symptoms in your body that are similar to those of your baby. Mirror syndrome is a dangerous condition that necessitates strict monitoring. The only way to treat it is to have your baby delivered.

If your child develops rhabdomyomas, doctors will want to gather your family’s genetic history to seek additional members of your baby's biological family who have or have had tuberous sclerosis. Your doctor may advise you to seek genetic counseling and maybe genetic testing to identify whether one of your parents has a mild case.

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Medically Reviewed on 4/6/2022
Image Source: iStock Images

Cardiac Rhabdomyoma: https://www.ncbi.nlm.nih.gov/books/NBK560609/

Cardiac Rhabdomyoma: https://my.clevelandclinic.org/health/diseases/22499-cardiac-rhabdomyoma

Neonatal cardiac rhabdomyoma: An unusual presentation: https://www.jcnonweb.com/article.asp?issn=2249-4847;year=2015;volume=4;issue=2;spage=123;epage=125;aulast=Balan