Cowden Syndrome

Cowden syndrome is a rare genetic (inherited) condition. People with Cowden syndrome often have many noncancerous, tumor-like growths and skin issues. They may also have an increased risk of developing certain cancers. They’ll need frequent cancer screening tests that may detect cancer before it causes symptoms.


What is Cowden syndrome?

Cowden syndrome is a rare genetic (inherited) condition. People with Cowden syndrome often have many noncancerous, tumor-like growths. They may also have an increased risk of developing certain cancers.

Is it common?

No. Cowden syndrome is rare. Experts estimate it affects 1 in 200,000 people. However, the condition is likely underdiagnosed because some healthcare providers may not recognize its symptoms.

Is Cowden syndrome cancer?

No. But people with Cowden syndrome have an increased risk of developing several kinds of early-onset cancer. “Early onset” means people develop disease at relatively young ages. For example, women and people assigned female at birth (AFAB) who have Cowden syndrome often develop breast cancer before age 40. Normally, you don’t get breast cancer before age 60. Other cancers linked to Cowden syndrome include:

What’s the difference between Cowden syndrome and PTEN hamartoma tumor syndrome?

PTEN hamartoma tumor syndrome (PHTS) is a group of inherited syndromes that involve genetic changes (mutations) to the PTEN gene. About 1 in 4 people with Cowden syndrome have the mutation on their PTEN gene. But because the symptoms are similar, if you have Cowden or Cowden-like syndrome, your healthcare provider will manage your condition like you had PHTS. This includes early and frequent screenings for certain cancers.


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Symptoms and Causes

What are Cowden syndrome symptoms?

Most people are in their 20s before they notice changes in their body that may be Cowden syndrome signs and symptoms. People may be diagnosed with Cowden syndrome after seeking medical care for hamartomas or early-onset cancer.

Hamartomas (pronounced “HA-mar-TOH-muhs”) are among the obvious and most common signs of Cowden syndrome. Hamartomas are noncancerous, tumor-like growths that can grow anywhere on or in your body but typically appear on your neck, face or head. Other Cowden syndrome symptoms include:

  • A large head (macrocephaly).
  • Small, smooth growths that form on your skin (trichilemmomas).
  • Clear bumps on the soles of your feet, palms and the back of your hands (acral keratosis).
  • Wart-like bumps on your tongue, gums, the back of your throat and your tonsils (oral papillomatosis).

It’s important to remember you may have some of these symptoms and not have Cowden syndrome. In general, healthcare providers may suspect Cowden syndrome if you have a combination of specific symptoms.

What causes Cowden syndrome?

Cowden syndrome happens when you inherit certain genetic mutations.

In Cowden syndrome, abnormal cells grow uncontrollably and don’t die when they normally would. Eventually, the cells form growths like hamartomas or noncancerous tumors.

Scientists are still learning about all the inherited gene changes that increase cancer risk, including those involved in Cowden syndrome. Some people with Cowden syndrome don’t have a mutated PTEN gene. In a small set of people with Cowden syndrome, researchers found other mutated genes, including PIK3CA/AKT1, SDHB-D, KLLN and SEC23B. Medical researchers continue to look for links between Cowden syndrome and other genetic mutations.

How do people inherit Cowden syndrome?

People with Cowden syndrome inherit the condition in an autosomal dominant pattern. In this case, people inherit a normal gene from one biological parent and a mutated gene from the other biological parent. That means they inherit one copy of the gene from each biological parent and have a 50% chance of inheriting the mutated gene.

What are the risk factors for Cowden syndrome?

The only known risk factor for Cowden syndrome is a family history of the condition.


What are the complications of this condition?

If you have Cowden syndrome, you have an increased risk of developing certain kinds of cancer. You may develop cancer at an early age and you may have more than one kind of cancer at different times in your life. Talk with your healthcare provider about the timing and frequency with which you’ll need cancer screening.

Diagnosis and Tests

How do healthcare providers diagnose Cowden syndrome?

Cowden syndrome is a complicated disease with several different symptoms and related conditions. You may have one or more of these conditions or symptoms, but that doesn’t mean you have Cowden syndrome.

To diagnose Cowden syndrome, healthcare providers compare your situation with diagnostic criteria developed by medical professionals who specialize in genetic (inherited) cancer syndromes. The process involves comparing your situation with major and minor criteria. A Cowden syndrome diagnosis means you have a specific combination of conditions.

Providers may suspect you have Cowden syndrome if you have:

  • Three of the major conditions, excluding macrocephaly.
  • One major condition or three minor conditions.
  • Four minor conditions.
  • A relative who has Cowden syndrome or related conditions like Bannayan-Riley-Ruvalcaba syndrome (BRRS).

Criteria for Cowden syndrome

Major criteria

  • Breast cancer.
  • Endometrial cancer.
  • Follicular thyroid cancer.
  • Many hamartomas in your gastrointestinal (GI) tract.
  • Macrocephaly.
  • Pigmented macule (darker spot) on the glans penis (head).
  • A biopsied trichilemmoma, meaning tissue samples studied under a microscope show signs of trichilemmoma.
  • Many spots of thickened skin on your hands and feet (palmoplantar keratosis).
  • Many wart-like growths in your mouth (oral mucosal papillomatosis).
  • Many wart-like growths on your face (cutaneous facial papules).

Minor criteria

  • Colon cancer.
  • Esophageal glycogenic acanthosis.
  • Autism spectrum disorder.
  • Learning disabilities.
  • Papillary thyroid cancer.
  • Thyroid issues such as goiters and adenomas.
  • Kidney cancer.
  • Lipomas.
  • A single hamartoma in your GI tract.
  • Testicular lipomatosis.

If your provider believes you may have Cowden syndrome, they’ll take your family history and order genetic testing to determine if you have a genetic mutation.

What should I do if I think I have Cowden syndrome?

It’s important to consult with a genetics professional so they can order PTEN gene testing. They’ll make sure you see a genetic counselor, who will help you understand how genetic conditions — like a PTEN mutation — might affect you. Your genetic counselor will also help you understand the results of any genetic testing, including what cancer screenings you’ll need if you have PTEN hamartoma tumor syndrome (PHTS). Because Cowden syndrome is rare, it’s a good idea to consult a team or center that specializes in PHTS and Cowden syndrome.


Management and Treatment

How do healthcare providers treat Cowden syndrome?

Cowden syndrome is linked to several different conditions, including skin issues and cancer. Often, people learn they have Cowden syndrome because they’re receiving treatment for conditions linked to the syndrome. But people with Cowden syndrome who don’t have cancer need regular, early cancer screenings, including:

  • Breast cancer: Annual mammogram starting at age 30. People with dense breasts may also have magnetic resonance imaging (MRI) scans.
  • Thyroid cancer: Annual thyroid ultrasound, starting at age 7, unless you have symptoms (like a lump in your thyroid or difficulty swallowing).


What can I expect if I have this condition?

If you have Cowden syndrome, your genetic counselor will help you understand the results of genetic testing. If genetic testing reveals that you have PTEN hamartoma tumor syndrome (PHTS), your genetic counselor will also help you understand what cancer screening tests you’ll need. You’ll start cancer screening at a younger age than most people. Regular screening may help providers detect cancer before you have symptoms.

What is the life expectancy for people with Cowden syndrome?

Life expectancy with Cowden syndrome depends on your situation. For example, if you have early-onset breast cancer that’s diagnosed after the cancer spreads, your life expectancy may be shorter than someone whose cancer was diagnosed and treated early on. However, following cancer screening guidelines helps prevent cancer or at least catch cancer at the earliest possible treatable stage.

Living With

How do I take care of myself?

If you have Cowden syndrome, you’ll need to have regular cancer screenings that detect cancer before it causes symptoms. Ask your healthcare provider if you should watch for specific signs and symptoms that may be cancer. If you have Cowden syndrome, ask your genetic counselor if your family members should have genetic testing.

Should I see my healthcare provider?

Cowden syndrome, especially those found to have a germline PTEN mutation or PTEN hamartoma tumor syndrome (PHTS), is linked to many kinds of cancer. Your healthcare team will closely monitor your overall health and regular cancer screening test results.

What questions should I ask my healthcare provider?

  • I have one kind of cancer because of this condition. Will I develop other kinds of cancer?
  • Genetic tests show I carry the mutated PTEN gene. Should my family be tested for this gene? Could this affect any biological children I might have?
  • I have Cowden syndrome but I don’t have a PTEN mutation. What genetic mutations may have caused this?
  • Genetic tests show I carry a mutated gene that causes Cowden syndrome. Does that mean I’ll have cancer?

A note from Cleveland Clinic

Cowden syndrome is a rare inherited disorder that can be difficult to diagnose. You should consult with a genetics professional who can determine if you have PTEN hamartoma tumor syndrome (PHTS). That way, your healthcare providers can tailor treatment to your situation. In some cases, such as when genetic tests don’t find PTEN mutations, you may need several kinds of tests so your providers can rule out other conditions. Your genetic counselor can help you understand next steps.

It can be frustrating to know there’s something going on in your body and not know what it is or what you should do. If you’re diagnosed with Cowden syndrome, you’ll live with the knowledge that you may develop different kinds of cancer during your lifetime. That’s an understandably frightening thought, even if you know there are screening tests that may find cancer even before you have symptoms. If you have this condition, your healthcare team will keep a close eye on your overall health and screening test results. They’ll move quickly to treat cancer before it spreads.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 03/14/2023.

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