Conditions · Obstetrics and gynecology
Gestational trophoblastic neoplasia (choriocarcinoma) !
A rare cancer that grows from placental tissue after a pregnancy, often after a molar pregnancy. It makes the pregnancy hormone hCG and is usually curable.
Updated 2026-11-01
Structures involved
Tap one to see what it is and open it in 3D.
Why it happens
- Invasion and metastasis: the metastatic cascade, step by step
- Tumour markers: serum and tissue, and what each one is for
- Pathways of spread and the usual metastatic sites
- The placenta and pregnancy hormones
- Placenta
What it is
The malignant end of gestational trophoblastic disease: trophoblast tissue that persists or invades after a pregnancy. It includes invasive mole, choriocarcinoma, placental-site trophoblastic tumour and epithelioid trophoblastic tumour. Choriocarcinoma is made of sheets of cytotrophoblast and syncytiotrophoblast without chorionic villi and spreads early through the blood.
Who gets it
Rare overall. About half of choriocarcinomas follow a complete hydatidiform mole and the rest follow a miscarriage, an ectopic pregnancy or a term pregnancy. Molar pregnancy, and therefore GTN, is reported more often in Latin America and Asia than in Europe and North America, so post-molar hCG follow-up is a routine part of obstetric care in Colombia.
Causes
- Persistent trophoblast after evacuation of a complete (more often) or partial hydatidiform mole
- Malignant change of trophoblast after miscarriage, ectopic pregnancy or a normal pregnancy
- Complete moles are androgenetic (all chromosomes paternal), which favours persistence
Risk factors
- Previous complete molar pregnancy
- Maternal age under 20 or over 35
- Previous gestational trophoblastic disease
- Very high hCG before mole evacuation and a uterus large for dates
- Large theca-lutein ovarian cysts at the time of the mole
Pathophysiology
Trophoblast normally invades the decidua and maternal spiral arteries in a controlled way and stops when the pregnancy ends. In GTN this control is lost: the cells keep proliferating, invade the myometrium and its vessels, and secrete hCG. Because they behave like placenta, they spread through the bloodstream, most often to the lungs, then the vagina, brain and liver. The tumour is very vascular, so metastases bleed easily. High hCG can stimulate the thyroid TSH receptor and the ovaries (theca-lutein cysts).
Classification
- Invasive mole (mole that invades the myometrium)
- Choriocarcinoma (no villi, early blood-borne spread)
- Placental-site trophoblastic tumour (low hCG, human placental lactogen, less chemosensitive)
- Epithelioid trophoblastic tumour
- FIGO anatomical stage I to IV plus the WHO prognostic score: low risk (0 to 6) or high risk (7 or more)
Symptoms and signs
- Irregular or persistent vaginal bleeding weeks to months after a pregnancy
- Uterus that stays enlarged and soft after delivery or evacuation
- Cough, haemoptysis or breathlessness from lung metastases
- Headache, seizures or focal deficits from brain metastases
- Purplish bleeding nodule in the vagina
- Signs of hyperthyroidism (tachycardia, tremor) when hCG is very high
Diagnosis
- Clinical
- Suspected in any woman with abnormal bleeding or unexplained metastatic disease after any pregnancy. After a molar pregnancy, GTN is diagnosed biochemically by the hCG curve (plateau or rise on serial measurements, or persistence for months), without needing a biopsy.
- Tests
- Serial quantitative serum beta-hCG is the key test and the tumour marker for response and follow-up. Complete blood count, liver, kidney and thyroid function. Biopsy of metastases is usually avoided because they bleed.
- Imaging
- Pelvic Doppler ultrasound (vascular myometrial mass) and chest radiograph to stage and count lung metastases; if lung metastases are present, brain and abdominal CT or MRI to look for brain and liver disease.
Differential diagnosis
- Persistent normal pregnancy or retained products of conception
- Ectopic pregnancy
- Non-gestational choriocarcinoma (ovarian germ cell tumour)
- Other cancers with lung metastases
- Phantom hCG (laboratory interference)
Goal of treatment
Bring hCG back to normal and keep it there, curing the disease while preserving fertility whenever possible, with treatment intensity set by the FIGO/WHO risk score.
Treatment
- Medical
- Low-risk disease: single-agent chemotherapy, classically methotrexate or dactinomycin, continued until hCG normalises and for a few consolidation cycles after that.
- Medical
- High-risk disease: multi-agent chemotherapy regimens (for example etoposide, methotrexate and dactinomycin combined with other agents), with intensified treatment for brain or liver metastases.
- Surgical
- Hysterectomy for women who do not want more children, for placental-site and epithelioid tumours (less sensitive to chemotherapy), or to control bleeding or resistant disease.
- Follow-up
- Serial hCG during and after treatment, with reliable contraception during follow-up so a new pregnancy does not confuse the hCG curve.
- Follow-up
- Safe handling of cytotoxic drugs, monitoring for bleeding, mucositis, infection and low blood counts, and emotional support around fertility.
Complications
- Severe haemorrhage (uterine, vaginal or from metastases)
- Respiratory failure from extensive lung metastases
- Intracranial haemorrhage from brain metastases
- Uterine perforation by invasive mole
- Hyperthyroidism or thyroid storm from very high hCG
- Relapse and chemotherapy toxicity
Prognosis
One of the most curable solid cancers. Low-risk GTN is cured in nearly all cases, usually with fertility preserved. High-risk disease is still cured in most women with combination chemotherapy; outlook is worse with brain or liver metastases, very high hCG or a long interval since the last pregnancy.
Prevention
- Prompt evacuation of molar pregnancies with weekly hCG follow-up until it normalises
- Contraception during the hCG follow-up period
- Measuring hCG in any woman with abnormal bleeding long after a pregnancy
Test yourself
Think of the answer, then tap the question to see it.
Which marker is used to diagnose and follow gestational trophoblastic neoplasia?
Quantitative serum beta-hCG, measured serially.
What is the most common site of metastasis of choriocarcinoma?
The lungs.
How is GTN diagnosed after a molar pregnancy?
By a plateau or rise of hCG on serial measurements; a biopsy is not needed.
What is the first-line treatment class for low-risk GTN?
Single-agent chemotherapy (methotrexate or dactinomycin).
Why is contraception advised during hCG follow-up?
A new pregnancy would raise hCG and hide a relapse.
Related conditions
- Molar pregnancy (hydatidiform mole)
- Miscarriage (early pregnancy loss)
- Ectopic pregnancy
- Hyperemesis gravidarum
- Graves disease (hyperthyroidism)
- Brain metastases
- Lung cancer
- Ovarian germ-cell and sex cord–stromal tumours
- Preeclampsia
Educational information, not medical advice. For any symptom, see a health professional.
Sources: Gestational Trophoblastic Disease Treatment (PDQ®)–Patient Version (National Cancer Institute, 2024); Choriocarcinoma (MedlinePlus (U.S. National Library of Medicine), 2024).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.
