Health condition
Placental site tumours
Placental site trophoblastic tumour is the rarest form of gestational trophoblastic disease, arising months or years after a pregnancy; unlike its chemotherapy-sensitive relatives, hysterectomy is the cornerstone of treatment, delivered through the UK’s national centres.
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.
The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.
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Can follow any pregnancy - normal birth, miscarriage or molar pregnancy - sometimes years later
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hCG levels are only modestly raised, unlike choriocarcinoma - a diagnostic trap
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Hysterectomy is the primary treatment because chemosensitivity is lower than other GTD
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The interval since the causative pregnancy is a key prognostic factor
Understanding the condition
What it is and what happens next.
What causes it, how it is diagnosed, and the treatment routes available in the UK.
What it is and how it feels
This tumour grows from the trophoblast cells that anchored a placenta to the womb, and its habits confound the usual trophoblastic rules: it may surface long after the pregnancy responsible, produces comparatively little hCG for its bulk, and presents mutedly - irregular bleeding, absent periods, or an incidental uterine mass. That combination, plus sheer rarity, makes histological diagnosis by pathologists within the specialist trophoblastic service essential.
Diagnosis and treatment routes
Treatment inverts the choriocarcinoma playbook: because these cells respond less reliably to chemotherapy, hysterectomy - with fertility inevitably in the balance for younger women - is the definitive act for disease confined to the uterus, with intensive multi-agent chemotherapy added for spread or adverse features, notably a long interval from the index pregnancy. The UK’s centralised registration and follow-up system, through Charing Cross and Sheffield, gives every patient access to this concentrated experience. If you are waiting for results or want a second opinion on a proposed plan, a private consultation with a specialist who treats this condition regularly can usually be arranged quickly, and most will review your existing scans, biopsy reports and MDT correspondence.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a consultant oncologist. 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 of the emergency symptoms described above.
Frequently asked
Common questions about Placental site tumours.
Quick, plain-English answers to what people ask us most.
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What are placental site tumours?
Placental site trophoblastic tumours are rare tumours arising from placental tissue that can persist or develop after a pregnancy, forming part of a group of conditions called gestational trophoblastic disease.
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What causes placental site tumours?
They arise from abnormal growth of trophoblastic cells, the cells that normally form part of the placenta, and can occur after a normal pregnancy, miscarriage, or molar pregnancy.
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What are the symptoms?
Irregular vaginal bleeding, sometimes occurring months after a pregnancy has ended, is the most common symptom, and it can also be identified through persistently abnormal pregnancy hormone (hCG) levels.
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Are placental site tumours dangerous?
Most are less aggressive than other forms of gestational trophoblastic disease, but they can occasionally spread and need appropriate specialist assessment and treatment to ensure a good outcome.
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Can placental site tumours be treated?
Yes, treatment usually involves surgical removal, often with hysterectomy in more established or spreading cases, and sometimes chemotherapy, depending on how the tumour behaves and whether it has spread.
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How are placental site tumours diagnosed?
Diagnosis often begins with persistently abnormal pregnancy hormone levels after a pregnancy has ended, followed by ultrasound or MRI imaging and, ultimately, tissue sampling to confirm the diagnosis.
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How long does treatment take?
This depends on the extent of disease and treatment needed, ranging from surgery alone with a relatively short recovery, to a longer course involving chemotherapy for more extensive disease.
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Placental site tumours vs a molar pregnancy — what's the difference?
A molar pregnancy is a different, more common form of gestational trophoblastic disease arising directly from abnormal fertilisation, while placental site tumours are rarer and can develop some time after a completed pregnancy, requiring separate diagnostic and treatment pathways.
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Will I need long-term follow-up after treatment?
Yes, regular monitoring of pregnancy hormone levels is typically continued for a period after treatment to ensure the condition has fully resolved and hasn't recurred.
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When should I see a specialist, and how quickly can I be seen privately?
See a specialist promptly for unexplained bleeding after a pregnancy has ended, particularly with abnormal hormone levels. Private gynaecological oncology assessment is typically available within about two weeks, faster than standard NHS specialist referral pathways.