A hamartoma is a noncancerous tumor made of an abnormal mixture of normal tissues and cells from the area in which it grows.

Hamartomas can grow on any part of the body, including the neck, face, and head. In some cases, hamartomas grow internally in places such as the heart, brain, and lungs.

Hamartomas sometimes disappear over time and show little to no symptoms. But in more severe cases, and depending on where they have grown, these growths can have serious complications.

Hamartoma tumors sometimes grow without causing any symptoms. The location of the tumor, however, can trigger some harmful side effects.

A common symptom from hamartoma growth is pressure, specifically when it begins pushing into other tissues or organs.

If it grows, a hamartoma can change the appearance of the breast.

In more severe cases, hamartoma growths can be life threatening.

Unlike malignant tumors, hamartomas don’t usually spread to other areas. However, they can cause pressure on surrounding organs or bodily structures.

  • Skin. Hamartomas can grow anywhere on the skin.
  • Neck and chest. Those that have grown on the neck can cause swelling and even give you a hoarse voice. If they grow on your chest, you may experience some respiratory issues or a chronic cough.
  • Heart. Hamartomas that grow on the heart can trigger heart failure symptoms. This is the most common heart tumor found in children.
  • Breast. A mammary hamartoma is a benign tumor found on the breast. While these tumors can appear at any age, mammary hamartomas are typically found in women 35 years and older. Usually found by accident, they can grow to large sizes and cause breast deformities. Breast hamartomas can also cause swelling.
  • Brain. Hamartomas on the brain can cause behavioral and mood changes. If they grow on the hypothalamus — the portion of the brain that controls many of your bodily functions — you may experience epileptic seizures. A common symptom is a seizure disguised as an uncontrollable laughing spell. Hypothalamic hamartomas can also trigger early puberty.
  • Lungs. Also referred to as pulmonary hamartomas, lung hamartomas are the most common benign lung tumors. It can cause you to have breathing issues and may trigger pneumonia. In more severe cases, you may cough up blood or your lung tissue may collapse.
  • Spleen. Splenic hamartomas, while rare, trigger symptoms in more women than men. Hamartomas found on the spleen can cause pain and discomfort in the abdominal region.

The exact cause of hamartoma growths is unknown, and cases are usually sporadic. These benign growths are associated with other conditions, including:

  • Pallister-Hall syndrome, a genetic disorder that affects bodily development and may cause you to have extra fingers or toes
  • Cowden syndrome, a condition that causes you to develop multiple benign growths
  • tuberous sclerosis

Hamartomas are difficult to diagnose without proper testing. These growths can resemble cancerous tumors and must be tested to confirm they aren’t malignant.

Some tests and procedures doctors may use to differentiate between these benign growths and cancerous tumors include:

Treatment for hamartoma tumors depends on the location they grow in and any harmful symptoms they cause.

In many cases, hamartomas cause no side effects and treatment is unnecessary. In this instance, doctors may take a “wait and watch” approach to observe the growth over time.

If you begin to experience seizures, doctors may prescribe anticonvulsants to reduce episodes. If you don’t respond to medication, surgical removal of the hamartoma may be required.

However, surgery is an invasive procedure that can cause life-threatening complications, depending on the size and location of the growth. Be sure to discuss your options with your doctor.

A less invasive option, specifically for hypothalamic hamartoma growths, is gamma knife radiosurgery. This procedure uses multiple radiation beams to destroy the tumor cells. The concentrated beams will shrink the hamartoma growths.

Hamartomas are noncancerous growths that can appear anywhere on the body. While seen as harmless, these benign tumors can grow to large sizes and cause pressure on surrounding tissues.

Depending on where they grow externally or internally, hamartomas can cause life-threatening symptoms.

If you notice an unusual growth or are experiencing the symptoms described, consult with your doctor immediately.