Health condition
Cowden syndrome
Cowden syndrome, the classic presentation of PTEN hamartoma tumour syndrome, combines benign overgrowths - skin papules, thyroid nodules, macrocephaly - with substantially raised risks of breast, thyroid and endometrial cancer that structured surveillance addresses.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
Which gene and test confirm it, who should be tested in the family, and which specialist to see.
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Caused by PTEN gene variants; autosomal dominant
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Recognisable features: head circumference above the 97th centile, facial trichilemmomas and oral papillomas, thyroid nodules or goitre, gastrointestinal hamartomas
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Cancer surveillance: annual thyroid ultrasound from diagnosis; for women, annual breast MRI/mammography from 30 and endometrial assessment from 35; colonoscopy from 35; renal imaging from 40
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Benign features usually need no treatment - their value is diagnostic
Understanding the condition
What it is and what happens next.
What causes it, how it is confirmed, and the testing and specialist routes available in the UK.
What it is and how it presents
Cowden syndrome is diagnosed by noticing combinations: any one feature is common in clinic populations, but a large head plus papular facial skin plus a nodular thyroid plus a family thread of early breast cancer forms a pattern that should end in a PTEN test rather than four unconnected referrals. For carriers, the stakes concentrate in surveillance - female breast cancer risk runs as high as any outside BRCA - and in knowing that bowel, kidney and skin each contribute smaller risks with their own schedule lines.
Testing, surveillance and specialist care
A confirmed diagnosis assembles the programme in one place: genetics coordinating breast, thyroid, gynaecological, bowel and renal surveillance, discussion of risk-reducing mastectomy where appropriate, and cascade testing so relatives - including those with only macrocephaly to show - learn their status with proper counselling. NHS clinical genetics services carry some of the longest waits in the health service, often many months for a first appointment, whereas private genetic testing and a specialist review can typically be arranged within around two weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a clinical geneticist. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any emergency symptoms.
Frequently asked
Common questions about Cowden syndrome.
Quick, plain-English answers to what people ask us most.
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What is Cowden syndrome?
Cowden syndrome is the classic presentation of PTEN hamartoma tumour syndrome, an inherited condition that combines benign overgrowths - such as skin papules and macrocephaly (a larger-than-average head) - with an increased lifetime risk of certain cancers, including breast, thyroid, and endometrial cancer.
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What causes Cowden syndrome?
Cowden syndrome is caused by an inherited mutation in the PTEN gene, which normally helps regulate cell growth. When this gene doesn't work properly, cells are more prone to overgrowth, leading to both benign lesions and increased cancer risk.
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What are the symptoms of Cowden syndrome?
Features can include multiple small skin growths (trichilemmomas and papules), a larger head circumference, benign thyroid nodules, gastrointestinal polyps, and macrocephaly, alongside the underlying increased cancer risk that often prompts diagnosis.
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Is Cowden syndrome dangerous?
The main concern is the significantly increased lifetime risk of certain cancers, particularly breast, thyroid, and endometrial cancer, which is why people with confirmed Cowden syndrome need structured surveillance rather than routine screening alone.
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Is Cowden syndrome hereditary?
Yes, it is inherited in an autosomal dominant pattern, meaning a child of an affected parent has a 50% chance of inheriting the PTEN mutation. Genetic counselling and testing are recommended for at-risk family members.
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Can Cowden syndrome be cured?
The underlying genetic change can't be reversed, but the increased cancer risk can be actively managed through enhanced surveillance (such as earlier and more frequent breast and thyroid screening) and prompt treatment of any lesions found.
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How is Cowden syndrome managed?
Management centres on a structured surveillance programme - typically including regular breast imaging, thyroid ultrasound, and colonoscopy from an earlier age than standard screening - alongside monitoring and, if needed, removal of benign or suspicious growths.
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How often does surveillance need to happen?
Surveillance schedules are individualised but often involve annual or biannual checks depending on the specific organ and personal/family history; a specialist genetics or oncology team will set out a tailored monitoring plan.
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Cowden syndrome vs other PTEN-related conditions - what's the difference?
Cowden syndrome is the most recognised presentation within the broader spectrum of PTEN hamartoma tumour syndromes, which also includes related but distinct presentations affecting different combinations of organs and features.
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When should I seek genetic assessment for possible Cowden syndrome?
Consider genetic assessment if you or a close relative have a personal or family history suggestive of Cowden syndrome, such as multiple related benign growths plus early breast or thyroid cancer. A private genetics consultation can often be arranged within about two weeks.