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.
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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.
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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.
Healthcare providers use different names to refer to hamartomas based on where they are in your body. Types include:
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.
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.
Several rare genetic syndromes increase your risk of getting hamartomas. They include:
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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.
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.
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:
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.
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:
Most hamartomas aren’t serious. But your experience depends on:
Your healthcare provider will let you know if you need treatment to remove it.
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.
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.
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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.
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Last reviewed on 08/29/2025.
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