Medical Oncologist
CION Cancer Clinics
The pigmented spots of Peutz-Jeghers: what they mean | CION Cancer Clinics
Small dark spots on the lips, inside the cheeks and on the fingers are often the first visible sign of Peutz-Jeghers syndrome. The spots are harmless and never become cancer. They matter because they point to polyps in the gut that do need checking. This page explains what the spots look like, how they differ from freckles, and what to do if you notice them. 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 do the dark spots on the lips mean in Peutz-Jeghers?
- What do the spots look like, and where do they appear?
- What happens next if a child has these spots?
- The words you will meet, in plain language
- How do these spots differ from ordinary freckles?
- What this page cannot tell you
- Four things families tell us, and what is actually true
- Common questions about the pigmented spots
The short answer
What do the dark spots on the lips mean in Peutz-Jeghers?
In Peutz-Jeghers syndrome, small dark brown or bluish spots appear on the lips, around the mouth, inside the cheeks and sometimes on the fingers and toes. The spots themselves are harmless and do not turn into cancer. What makes them important is that they are a clue. In a child with the right pattern, they can point doctors to the syndrome before polyps in the gut cause any trouble.
Why the spots appear
The same gene fault that causes the polyps, in a gene called STK11, also affects the cells that make skin colour. In small patches, those cells make more pigment than usual. It has nothing to do with the sun, diet or anything the family did.
How they change with age
The spots usually appear in the first few years of life, and can become more noticeable through early childhood. Many fade during the teenage years and adulthood. The spots inside the cheeks tend to stay, which is why a doctor who suspects the syndrome will always ask to look inside the mouth.
The spots are a signpost, not a problem in themselves.What to look for
What do the spots look like, and where do they appear?
They are flat, small and darker than the surrounding skin. Where they sit is what makes them distinctive.
On the lips and around the mouth
The most common place. Spots cluster on the lips, often crossing the edge where lip meets skin, and around the mouth and nostrils. On brown skin they can look like ordinary darker patches and be overlooked.
Usually looks like
- Flat, not raised
- Dark brown, grey or bluish
- Crowded together in one area
Inside the cheeks and on the gums
This is the telling sign. Ordinary freckles do not appear inside the mouth. Spots here also tend to last into adult life, after the ones on the face have faded.
Fingers, toes, palms and soles
Some people have spots on the fingertips, the palms, the soles of the feet or the toes. These are easy to miss unless someone looks for them on purpose.
Around the eyes and the bottom
Less often, spots appear around the eyes or around the anus. They mean the same thing as spots anywhere else and need no treatment. They do not itch, bleed or hurt.
Not sure whether this applies to you?
Ask an oncologistIf you have noticed them
What happens next if a child has these spots?
A doctor looks closely
The lips, the inside of the cheeks, the fingers and the feet are examined. You will be asked when the spots first appeared, and whether the child has had tummy pain, bleeding or tiredness.
The family history is drawn out
The doctor asks about relatives with bowel polyps, a bowel blockage in childhood, or cancer at a young age. Spots together with that kind of family history are often enough to make the diagnosis.
Genetic counselling and a blood test
A counsellor explains the test first. A blood sample is then checked for a fault in STK11. Testing a child makes sense here, because the first gut checks begin in childhood.
A plan is made
If the syndrome is confirmed, planned gut checks are booked. If the test is negative but the picture still fits, the doctor may advise checks anyway, because the diagnosis can be made without a gene result.
On the report
The words you will meet, in plain language
- Mucocutaneous pigmentation
- Dark spots on the skin and on the moist lining of the mouth. This is how doctors describe the spots in their notes.
- Macule
- A flat spot of different colour that you can see but not feel.
- Buccal mucosa
- The inner lining of the cheeks. Spots here are the most useful sign, because ordinary freckles never appear there.
- STK11
- The gene that is faulty in most people with Peutz-Jeghers. It acts as a brake on cell growth in many tissues.
- Hamartomatous polyp
- The type of polyp seen in this syndrome. It is an overgrowth of normal tissue, mostly in the small bowel.
- Clinical diagnosis
- A diagnosis made from what doctors see and the family history, without needing a positive gene test.
Leave a number, we will call you
One field. No form to fill in, and no charge for the call.
Side by side
How do these spots differ from ordinary freckles?
Peutz-Jeghers spots
Ordinary freckles
On the lips and inside the mouth
On sun-exposed skin, never inside the mouth
Appear in early childhood, sun or no sun
Appear with sunlight and darken in summer
Often fade after puberty, except inside the cheeks
Come and go with the seasons
Can appear on the palms, soles and fingertips
Rare on the palms and soles
A clue to a syndrome that needs checks
Harmless and need nothing
Being straight with you
What this page cannot tell you
It cannot tell you whether the spots on your child's lips are Peutz-Jeghers. That needs a doctor to examine them in person, take a family history and, if it still looks possible, arrange genetic counselling. A photograph sent on WhatsApp is not enough to decide either way.
Other things look similar
A few other conditions cause dark spots on the lips. One is a harmless condition in which similar spots first appear in adult life, with no polyps. Another is a different inherited condition that affects the heart and hormone glands. In adults, tobacco chewing, smoking and some medicines can also darken the lips. Telling these apart is a job for a specialist. What your specific gene variant means is a question for the counsellor who ordered the test.
Who this does not apply to
Most children with freckles on the face do not have Peutz-Jeghers. Spots only on sun-exposed skin, with nothing inside the mouth and no family history of polyps or bowel blockage, are very unlikely to mean anything. An adult whose lips darken for the first time in middle age almost certainly does not have this syndrome, though a doctor should still look.
Commonly believed
Four things families tell us, and what is actually true
"The spots will turn into skin cancer."
They will not. The spots are harmless. The cancer risk in Peutz-Jeghers lies in internal organs such as the bowel, breast and pancreas, which is what the planned checks watch.
"Her spots have faded, so the condition has gone."
Fading is normal with age and changes nothing. The gene fault is still there, polyps keep forming, and the checks need to carry on.
"He has no spots, so he cannot have it."
Most people with the syndrome have spots, but not all. On darker skin they can be faint and easy to miss. A brother or sister in an affected family needs a genetic test, not just a look at their lips.
"Laser treatment will remove the problem."
Laser can lighten the spots on the skin if they bother someone. It is cosmetic only. It does nothing to the polyps or the cancer risk, and the spots can return.
Questions we are asked
Common questions about the pigmented spots
Are the spots dangerous?
No. The spots are harmless, do not become cancer and need no treatment. They matter because they can be the first visible sign of Peutz-Jeghers syndrome, which does need planned checks of the gut. A child with suspicious spots should be seen by a doctor without delay, but not in a panic.
At what age do the spots appear?
Usually in infancy or the first few years of childhood. They often become more noticeable as the child grows, and many fade during the teenage years or adulthood. The spots inside the cheeks tend to stay. Spots that appear for the first time in adult life usually have another cause.
Can the spots be removed?
Laser treatment can lighten the spots on the lips and skin, and some people choose it for confidence. It may need several visits and the spots can return. On brown skin, choose a dermatologist experienced in treating darker skin, to lower the chance of patchy colour afterwards.
My child has lip freckles but no tummy problems. Should we test?
Ask a doctor to look first, including inside the mouth. If the pattern fits, or there is a family history of polyps or bowel blockage, a referral for genetic counselling makes sense even without symptoms. Large polyps often grow silently, which is exactly why an early answer helps.
Does everyone with Peutz-Jeghers have the spots?
The great majority do, which is why the spots are such a useful clue. A few people have faint spots or none that anyone noticed. So the absence of spots does not rule the syndrome out in a family where it has already been found.
Should brothers and sisters be checked?
If the syndrome is confirmed and a parent carries it, each child has a one in two chance of inheriting it. Their brothers and sisters should be offered a test for the family's gene fault. If neither parent carries it, the risk to siblings is low, and a counsellor will explain why.
Do sunlight or food make the spots worse?
The spots are not caused by the sun or by food, and no diet removes them. Sunlight can darken any skin, including the spots on the face, so ordinary sun protection is reasonable. It will not change the syndrome in any way.
Who should we see first in Hyderabad?
A paediatrician or a gastroenterologist is a good first stop, and they can refer on for genetic counselling. Take photographs of the spots from when they first appeared if you have them. Call the CION helpline if you are not sure who to approach.
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) — Peutz-Jeghers Syndrome
- MedlinePlus Genetics — Peutz-Jeghers syndrome
- MedlinePlus Genetics — STK11 gene
- National Cancer Institute — Genetics of Colorectal Cancer (PDQ) - Health Professional Version
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
Peutz-Jeghers syndrome explainedWhat the syndrome is, beyond the spotsWhat the STK11 gene doesThe gene behind both the spots and the polypsSmall bowel surveillance and balloon enteroscopyThe checks that follow a diagnosisLiving with Peutz-Jeghers from childhoodSchool, feelings and the spots, as a child grows
Talk to us
Noticed spots like these on your child?
Describe where the spots are and whether anyone in the family has had bowel polyps. We will tell you honestly whether a referral is worth making, and arrange it if it is. One helpline serves every CION centre.