A hamartoma is a noncancerous growth that’s made of the same cells found in surrounding tissue. The cells and tissue just grow in a disorganized way. Most don’t cause symptoms and aren’t serious. If a hamartoma is causing problems, surgery usually resolves the issue.

What Is a Hamartoma?

A hamartoma (“ham-ar-TOE-muh”) is a tumor-like growth that can appear anywhere in your body. When people hear the word “tumor,” many think of cancer. But hamartomas aren’t cancer. They’re just a mix of the same cells and tissues that belong in the part of your body where they form. They just grow in a disorganized way.

Hamartomas are mostly harmless. But they can cause issues if they’re big enough to damage nearby tissue. Sometimes, they’re a sign of rare genetic conditions linked to increased cancer risk.

Your healthcare provider will tell you if you have a hamartoma that poses risks. If you do, they’ll likely remove it with surgery.

Types of this condition

Healthcare providers use different names to refer to hamartomas based on where they are in your body. Types include:

Symptoms and Causes

Symptoms of hamartomas

Most hamartomas don’t cause symptoms unless they grow so big that they affect nearby tissue. If you do have symptoms, they’ll usually relate to the part of your body where the hamartoma is.

Hamartoma causes

Experts don’t know what causes them in all cases. They do know that some genetic conditions linked to hamartomas involve inheriting a gene mutation from one of your biological parents.

Risk factors

Several rare genetic syndromes increase your risk of getting hamartomas. They include:

  • Neurofibromatosis Type 1 (NF1): Hamartomas most often grow on nerves in your brain, spinal cord and skin.
  • Pallister-Hall syndrome (PHS): Hamartomas may grow on a part of your brain called the hypothalamus. This type is called hypothalamic hamartoma.
  • Peutz-Jeghers syndrome (PJS): You’re at increased risk of developing hamartomas in your bladder, intestines, lungs and stomach.
  • PTEN hamartoma tumor syndrome (PHTS): Hamartomas can form in different parts of your body, like your breasts, GI tract, skin, thyroid and uterus.
  • Tuberous sclerosis: Hamartomas may form in various organs, including your eyes, brain, heart, kidneys and skin.

Some of these syndromes increase your cancer risk. But it’s the condition — not the hamartoma — that’s linked to cancer. You might need regular checkups and cancer screenings.

Complications of this condition

Most hamartomas aren’t serious. But they can cause issues if they damage nearby tissue or organs.

For example, hypothalamic hamartomas can lead to seizures and developmental delays in children. Cardiac rhabdomyomas may interfere with blood flow in your heart.

Healthcare providers remove hamartomas that cause symptoms and other health issues.

Diagnosis and Tests

How doctors diagnose this condition

Healthcare providers often discover hamartomas during imaging for an unrelated issue. Or you may see your provider if you have symptoms. You may need more imaging to confirm the diagnosis.

Imaging tests you may need include:

  • Computed tomography (CT) scan
  • Magnetic resonance imaging (MRI)
  • Mammogram
  • Ultrasound
  • X-ray

You may need a biopsy if your provider can’t be sure that the growth isn’t cancer. They’ll remove some of the tissue. Then, they’ll send it to a lab for testing.

Management and Treatment

How are hamartomas treated?

Most people don’t need treatment unless the hamartoma is causing symptoms. If it’s causing issues, you’ll likely need surgery to remove it.

Sometimes, surgery is too risky because the hamartoma is close to important tissue. For example, some brain hamartomas grow close to the nerve that connects your eyes to your brain. Surgery may risk damaging the nerve. If that’s the case, your provider may suggest:

Outlook / Prognosis

What can I expect if I have this condition?

Most hamartomas aren’t serious. But your experience depends on:

  • Where the hamartoma is
  • Whether it’s causing symptoms
  • Whether it’s related to a rare genetic syndrome that requires lifelong management

Your healthcare provider will let you know if you need treatment to remove it.

Can a hamartoma turn cancerous?

It’s possible. But this is rare.

Hamartomas aren’t usually serious. But some conditions that cause hamartomas may increase your cancer risk. For example, PTEN hamartoma tumor syndrome (PHTS) can cause these growths throughout your body. PHTS also increases your cancer risk.

It’s the condition that relates to cancer risk, not the hamartoma.

Additional Common Questions

What is the difference between a hamartoma and a neoplasm?

Both hamartomas and neoplasms are overgrowths of tissue. Neoplasms (tumors) happen when abnormal cells form a mass in your body. Tumors can be benign (not cancer) or cancerous. But hamartomas are made of normal cells and tissue that are native to the part of your body where they start. The cells and tissue just grow together in an odd way.

Like benign tumors, hamartomas tend to grow slowly. They don’t spread throughout your body like cancerous tumors sometimes do.

A note from Wockr

It can feel scary when an imaging test reveals an odd growth, like a hamartoma. But it’s important to remember that not all growths mean cancer. Hamartomas are usually harmless. Most people don’t need surgery to remove them. But if you do, surgery usually improves symptoms. If you get this diagnosis, ask your healthcare provider what it means for your health.