Medical Oncologist
CION Cancer Clinics
Gardner syndrome: the features outside the bowel | CION Cancer Clinics
Gardner syndrome is a form of familial adenomatous polyposis, or FAP, where features outside the bowel are easy to see. These include bony lumps on the jaw, extra teeth, skin cysts and desmoid tumours. It comes from the same APC gene fault, and the bowel risk is the same. This page explains each feature, which ones matter, and why a dentist is sometimes the first to spot it. At CION Cancer Clinics, our oncologists plan screening and care for families with an inherited cancer syndrome, explained in plain words.
NG
Medically reviewed by Dr. Naresh GunduConsultant Medical Oncologist · MBBS, DNB (Internal Medicine), DM (Medical Oncology, AIIMS) · last reviewed September 2026, next review due September 2027
17+specialists on panel
15,000+patients treated
35+centres across Telangana & AP
4.8★ / 800+Google rating
On this page
- What is Gardner syndrome?
- Which features outside the bowel point to Gardner syndrome?
- How does Gardner syndrome usually come to light?
- The words you will meet, in plain language
- Which features need action, and which only need noting?
- What this page cannot tell you
- Four things families tell us, and what is actually true
- Common questions about Gardner syndrome
The short answer
What is Gardner syndrome?
Gardner syndrome is familial adenomatous polyposis, or FAP, with noticeable features outside the bowel. These include bony lumps, extra teeth, skin cysts and desmoid tumours. It is caused by a fault in the same APC gene, and the bowel risk is the same as in FAP.
Why there are two names
Doctors first described Gardner syndrome before the gene was known. They thought families with bone and skin lumps had a separate condition. Once testing became possible, the same APC gene turned up in both groups. Today most specialists treat Gardner syndrome as one way FAP can show itself, and some reports no longer use the older name at all.
Why the features still matter
The features outside the bowel often appear first, sometimes in early childhood. A dentist looking at an X-ray, or a skin doctor removing a cyst from a child, may be the first person to suspect FAP. Picking it up at that point means bowel checks can begin before any polyp has had time to turn into cancer.
The label changes nothing about bowel care. Anyone with Gardner features follows the same plan as anyone with FAP.What to look for
Which features outside the bowel point to Gardner syndrome?
None of these features is dangerous on its own, apart from desmoid tumours. Together, in one person or one family, they are a strong clue.
Bony lumps
Hard, painless lumps of extra bone, called osteomas. They are most often felt on the jaw or the skull. They are not cancer and rarely need treatment.
Teeth
Dental X-rays often show changes before anything else does.
- Extra teeth that were never expected
- Teeth that stay buried in the jaw
- Small tooth-like growths inside the jawbone
Skin lumps
Soft, round cysts under the skin. In most adults a cyst means nothing. In Gardner syndrome they appear in childhood, often several at once, on the face, scalp, arms or legs.
Desmoid tumours
Firm growths in the belly wall or deeper inside the abdomen. They do not spread like cancer, but they can grow into nearby tissue and press on organs. They need specialist care.
Not sure whether this applies to you?
Ask an oncologistHow it is picked up
How does Gardner syndrome usually come to light?
-
Someone outside bowel care notices something
A dentist sees extra or buried teeth on an X-ray. A skin doctor removes several cysts from a child. An eye doctor notices dark spots at the back of the eye.
-
The family history is asked about
The right question is whether anyone had bowel polyps or bowel cancer young. Families often remember a relative who died early of a stomach illness that was never named.
-
A colonoscopy looks for polyps
For a teenager or adult, a camera test of the bowel shows whether polyps are present and how many. In a younger child, the team decides when this should be done.
-
A blood test looks for the APC fault
A genetic test confirms the diagnosis. Once the exact fault is known, parents, brothers, sisters and children can be tested for it.
-
Care follows the FAP plan
Bowel checks, planned surgery, upper gut checks and thyroid scans follow as for anyone with FAP, with extra attention to desmoid tumours.
On your report
The words you will meet, in plain language
- Osteoma
- A harmless lump of extra bone, usually on the jaw or skull. It is not a bone cancer.
- Odontoma
- A small growth made of tooth material, sitting inside the jawbone. It is usually found on a dental X-ray.
- Epidermoid cyst
- A soft, round lump under the skin, filled with skin material. It is harmless but can become sore.
- Desmoid tumour
- A growth of the tissue that holds the body together. It does not spread like cancer but can grow locally.
- Fibroma
- A small, firm lump of the same connective tissue. It is harmless and is removed only if it bothers you.
- CHRPE
- Flat, dark patches at the back of the eye, present from birth. They do not affect sight and need no treatment.
Leave a number, we will call you
One field. No form to fill in, and no charge for the call.
Side by side
Which features need action, and which only need noting?
Feature
What usually happens
Bony lumps on the jaw or skull
Noted and left alone unless painful or unsightly
Extra or buried teeth
Planned dental care, with the dentist told about FAP
Skin cysts
Removed only if sore, infected or bothersome
Desmoid tumours
Watched closely by a specialist team, often without surgery first
Dark spots in the eye
Noted as a clue, with no treatment needed
Being straight with you
What this page cannot tell you
It cannot tell you whether a lump, a cyst or an extra tooth in your child means FAP. That needs a doctor to examine them, ask about the family and, where there is reason to, arrange a genetic test. Nobody can diagnose Gardner syndrome from a photograph or a single X-ray.
It cannot predict which features a person will have
Two relatives with the same APC fault can look very different. One may have several cysts and bony lumps, and the other none at all. The bowel risk is the same for both. What your specific variant means is a question for the counsellor who ordered the test.
Who this does not apply to
Most children with one extra tooth or one skin cyst do not have FAP. These are common findings on their own. The pattern that matters is several features together, or one feature alongside a family history of bowel polyps or bowel cancer at a young age.
If your dentist or skin doctor has raised FAP, bring their note and any X-rays to the counselling appointment.Commonly believed
Four things families tell us, and what is actually true
"Gardner syndrome is milder than FAP because it is mostly lumps."
The bowel risk is the same. The lumps and cysts are the visible part, but the polyps inside the bowel need exactly the same checks and planning as in anyone with FAP.
"A bony lump on the jaw must be bone cancer."
Osteomas are harmless growths of normal bone. They can look alarming on an X-ray, but they do not spread and most never need to be removed.
"A desmoid tumour is a cancer that will spread."
Desmoids do not spread to distant organs. They can still cause real problems by growing into nearby tissue, which is why they are managed by a specialist team.
"If my child has no cysts or lumps, they do not have it."
Many people with the APC fault never develop any feature outside the bowel. Only a genetic test can say whether a child in an FAP family carries the fault.
Questions we are asked
Common questions about Gardner syndrome
Is Gardner syndrome different from FAP?
Not in the way that matters. Both are caused by a fault in the APC gene, and both carry the same bowel risk. Gardner syndrome is the name used when features outside the bowel, such as bony lumps and skin cysts, are noticeable. Care follows the FAP plan either way.
My dentist found extra teeth on my child's X-ray. Should I worry?
On their own, extra teeth are common and usually mean nothing. Mention it to a doctor if anyone in the family has had bowel polyps or bowel cancer young, or if your child also has skin cysts or bony lumps. That combination is worth a referral.
Are the bony lumps a type of cancer?
No. Osteomas are made of normal bone and do not spread. They are removed only if they cause pain, affect chewing or change the shape of the face in a way that bothers the person. Many people live with them untouched.
Do the skin cysts need to be removed?
Only if they become sore, infected or bothersome. Removal is a small procedure. It is worth telling the doctor removing them about FAP, because it may change how they plan any operation and what they look for.
What is a desmoid tumour, and is it serious?
It is a growth of connective tissue, often in the belly wall or inside the abdomen. It does not spread like cancer, but it can press on the bowel or blood vessels. Surgery and pregnancy can sometimes trigger one, which is why teams plan operations with this in mind.
Does Gardner syndrome need a different gene test?
No. The same APC test is used. The laboratory looks for a fault in that gene, and the result does not depend on which features you have. Relatives are then tested for the exact fault found in the family.
Can the features appear before the bowel polyps?
Yes, and this is why they are so useful. Bony lumps, extra teeth and skin cysts can be present in early childhood, well before polyps would be seen at colonoscopy. Spotting them early gives the family time to plan testing and checks.
Who should we see first?
A genetic counsellor or a bowel specialist is the right starting point, even if a dentist raised the question. Bring any X-rays and reports. Call the CION helpline if you are not sure where to begin, and someone will direct you.
Your Specialists
Meet CION's oncologists. Bring your family history or genetic report to them.
Our medical oncologists see people with a strong family history of cancer, arrange genetic counselling and testing where it fits, and plan the checks that follow.
Medical Oncologist
Dr. C. Raghavendra Reddy
MBBS(Gold Medal), DNB(General Medicine), DM(Medical Oncology)(Gold Medal)
Medical Oncologist
Dr. Bharati Devi Gorantla
MBBS, MD(General Medicine), DM(Medical Oncology)(Adyar,Chennai), ECMO, MRCP SCE(UK)
Medical Oncologist
Dr. Owais Mohammed
MBBS, MD (General Medicine), DrNB (Medical Oncology), ECMO, MRCP SCE (Medical Oncology) (UK)
Medical Oncologist
Medical Oncologist
Want a specific doctor for your case? Mention them when booking.
Book Free ConsultationBook an appointment with our specialist
Share your name and number — we'll call you back within 30 minutes to schedule your consultation.
Sources
- GeneReviews (NCBI) — APC-Associated Polyposis Conditions
- MedlinePlus Genetics — Familial adenomatous polyposis
- MedlinePlus Genetics — Desmoid tumor
- National Cancer Institute — Genetics of Colorectal Cancer (PDQ)
This page is general information, not a prescription. Do not change or stop any treatment based on what you read here. If anything is worrying you, contact your own treating team — or call our helpline and we will help you reach the right specialist.
Keep reading
Related pages
Familial adenomatous polyposis explainedThe condition Gardner syndrome belongs to, from the startDesmoid tumours and the APC geneThe one feature outside the bowel that needs specialist careTurcot syndrome and brain tumour riskThe other older name for a form of FAPThyroid screening in FAPAnother check that applies whatever the label
Talk to us
Has a dentist or skin doctor mentioned FAP?
Tell us what was found and whether anyone in the family had bowel polyps young. We will help you decide whether a genetic referral is needed and arrange it if so. One helpline serves every CION centre.