Medical Oncologist
CION Cancer Clinics
PTEN hamartoma tumour syndrome: one cause, several names | CION Cancer Clinics
PTEN hamartoma tumour syndrome, or PHTS, is the umbrella name for conditions caused by an inherited fault in the PTEN gene. Cowden syndrome is the best known of them. They share one cause but can look very different, from a child with a large head to an adult with thyroid nodules. This page explains what sits under the umbrella and why doctors now use one name. At CION Cancer Clinics, our oncologists explain what a gene result means for you and your family, and plan the checks that follow.
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 does PTEN hamartoma tumour syndrome actually mean?
- Which conditions are grouped together as PHTS?
- Why the same fault looks so different at different ages
- The words you will meet, in plain language
- Diagnosed by a gene test, or by features alone?
- What this page cannot tell you
- Four things families tell us, and what is actually true
- Common questions about PTEN hamartoma tumour syndrome
The short answer
What does PTEN hamartoma tumour syndrome actually mean?
PTEN hamartoma tumour syndrome is one name for several conditions that share a single cause: an inherited fault in the PTEN gene. Doctors often shorten it to PHTS. Cowden syndrome is the best known condition under the umbrella, and most adults with a PTEN fault are described this way.
Why doctors moved to one name
For years these conditions were diagnosed separately, by their features. One child was labelled one way because of a large head and freckling. An adult in the same family was labelled another way because of thyroid nodules and skin bumps. Once testing showed the same gene fault in both, it made sense to treat them as one condition that shows itself differently at different ages.
What a hamartoma is
A hamartoma is a non-cancerous growth made of the tissue that normally belongs in that spot, arranged in a disorganised way. People with a PTEN fault tend to form them in the skin, the bowel, the thyroid and elsewhere. Most are harmless. The reason the syndrome matters is that the same fault also raises the risk of certain cancers.
The umbrella name changes nothing about care. The surveillance plan follows the PTEN fault, whatever label is on the letter.Under the umbrella
Which conditions are grouped together as PHTS?
Each of these was once thought of as its own condition. A PTEN fault links them.
Cowden syndrome
The adult picture. Skin bumps on the face and hands, thyroid nodules, bowel polyps and a raised risk of breast, thyroid, womb, kidney and bowel cancer.
Usually noticed through
- A cancer diagnosed younger than expected
- Characteristic skin findings
- A large head measured at a clinic visit
Bannayan-Riley-Ruvalcaba syndrome
The childhood picture. A large head, benign fatty lumps, freckling on the penis in boys, and sometimes developmental delay. Many of these children later show the adult features too.
Proteus-like overgrowth
A small number of people with uneven overgrowth of one part of the body carry a PTEN fault. Classic Proteus syndrome itself has a different cause and is not part of PHTS.
Autism with a large head
Some children with autism and a noticeably large head carry a PTEN fault. Finding it matters, because it means cancer surveillance will be needed in adult life.
A large head alone is common and is rarely a PTEN fault.Not sure whether this applies to you?
Ask an oncologistAcross a lifetime
Why the same fault looks so different at different ages
-
In early childhood
The most common sign is a head size above the usual range. Some children also have developmental delay, low muscle tone or features of autism. Cancer is not the concern at this age.
-
In later childhood and the teenage years
Benign fatty lumps, raised skin bumps and thyroid nodules can start to appear. Thyroid checks usually begin in childhood for this reason.
-
In early adult life
Skin findings on the face, hands and feet become more obvious. Bowel polyps may be found. Breast changes and womb fibroids are common in women.
-
From the thirties onwards
Cancer risk rises, most of all for the breast and the thyroid, and later for the womb, kidney and bowel. This is when most planned screening is concentrated.
-
Which is why one label was never enough
A family seen at different moments looked like it had different illnesses. One gene test now joins the picture up.
On your report
The words you will meet, in plain language
- PTEN
- A gene that acts as a brake on cell growth. When one copy is faulty, cells in several organs grow a little more than they should.
- Hamartoma
- A non-cancerous growth made of normal tissue in a disorganised arrangement.
- Macrocephaly
- A head size above the usual range for age and sex. It is one of the most common features of PHTS.
- Trichilemmoma
- A small harmless skin bump, usually on the face, that grows from a hair follicle. A skin biopsy can confirm it.
- Germline
- Present in every cell from birth, and therefore able to be passed on. This is different from a fault found only inside a tumour.
- De novo
- A fault that appeared for the first time in this person. Neither parent carries it, but their children can inherit it.
Leave a number, we will call you
One field. No form to fill in, and no charge for the call.
Side by side
Diagnosed by a gene test, or by features alone?
A PTEN fault is found
Features only, no fault found
The diagnosis is PHTS, whatever the features
A clinical diagnosis of Cowden syndrome may still be made
Relatives can be tested for that exact fault
Relatives are advised using the family history
Surveillance follows PTEN guidance
Surveillance is often similar, based on the features
Children can be offered testing early
Children are watched for signs instead
Being straight with you
What this page cannot tell you
It cannot tell you whether you or your child has PHTS. That is decided by a clinical geneticist who examines the person, measures the head, looks at the skin, draws the family tree and, in most cases, arranges a PTEN test. Several features overlap with common, harmless findings, so a checklist read at home is easily misleading.
It cannot interpret a report you are holding
PTEN reports can list a variant whose meaning is still uncertain. What your specific variant means is a question for the counsellor who ordered the test. Searching for the variant name online tends to raise more fear than it settles.
Who this does not apply to
Most people with a large head, a few skin tags or a thyroid nodule do not have PHTS. All three are common on their own. The syndrome becomes a real question when several features appear together, or alongside an unusual family history of breast, thyroid or womb cancer.
Commonly believed
Four things families tell us, and what is actually true
"Cowden syndrome and PHTS are two different diagnoses."
They describe the same underlying fault. Cowden syndrome is one way PHTS can show itself, usually in adults.
"Nobody else in our family has it, so it cannot be genetic."
A PTEN fault is fairly often new in the person who has it. Their parents test negative, yet their children can still inherit it.
"A child with PHTS will get cancer as a child."
Childhood cancer is not the main concern. The thyroid is checked from childhood, but most cancer risk sits in adult life.
"The skin bumps will turn into cancer."
The typical skin findings are harmless. They matter as clues to the diagnosis, not as a threat in themselves.
Questions we are asked
Common questions about PTEN hamartoma tumour syndrome
Is PHTS the same as Cowden syndrome?
Not exactly. PHTS is the umbrella term for every condition caused by a PTEN fault. Cowden syndrome is the best known of them and is the label most adults receive. If your report says PTEN pathogenic variant, you have PHTS, whichever name the letter uses.
How is PHTS passed on in a family?
It is inherited in a dominant way. Each child of a person with a PTEN fault has a one in two chance of inheriting it. Boys and girls are equally likely to inherit it, and a parent can pass it on whether or not they have had cancer.
Which cancers does a PTEN fault raise the risk of?
Breast and thyroid cancer carry the biggest rise in risk. Womb, kidney and bowel cancer and melanoma are also raised. The size of each risk varies between studies, so your counsellor will explain it against your own family history.
Can PHTS be diagnosed without a gene test?
Yes. Doctors use published lists of major and minor features to make a clinical diagnosis. A gene test is still usually offered, because a confirmed fault lets relatives be tested precisely.
What is Lhermitte-Duclos disease?
A rare, non-cancerous growth in the part of the brain that controls balance. It is strongly linked to PTEN faults in adults. It is uncommon, so a brain scan is usually arranged only if there are symptoms such as unsteadiness or headaches.
Does PHTS affect learning and development?
In some children it does. Developmental delay and autism are more common with a PTEN fault, especially when found in childhood. A developmental assessment is often suggested at diagnosis so that support can start early.
Is there a treatment for the syndrome itself?
The gene fault cannot be corrected or reversed. Care means regular checks of the organs at risk, removing growths that cause problems, and finding any cancer early. Some drugs that act on the same growth pathway are being studied, but none is routine care.
Who should we see first in Hyderabad?
Start with a genetic counsellor or clinical geneticist, taking any reports and a list of who in the family had which cancer. If you are not sure where to begin, call the CION helpline and someone will point you to the right clinic.
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) — PTEN Hamartoma Tumor Syndrome
- MedlinePlus Genetics — PTEN gene
- MedlinePlus Genetics — Cowden syndrome
- National Cancer Institute — Genetics of Breast and Gynecologic Cancers (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
Talk to us
Were you told a family member may have PHTS?
Tell us what the letter or report says and who in the family is affected. We will help you reach a genetic counsellor who can explain it properly. One helpline serves every CION centre.