Gestational trophoblastic disease Flashcards
Definitions:
1. Gestational trophoblastic disease
- Gestational trophoblastic disease: uncommon tumours of placental tissue
Incidence
1: 200-1:1000 pregnancies
1: 50,000 after term birth
Risk factors
- Asian women have higher incidence (1/390 vs 1/750 for non asian)
- Aged less than 15 or over 45
- Previous GTD (recurrence rate 1:70)
Management of suspected partial/complete molar pregnancy
- Suction evacuation
Avoid oxytocic until after completion of evacuation
as may increase the risk of embolisation
Baseline quantitative serum βhGG, FBC, Group and Hold
If clinically indicated: TFT, LFT, Coag, CXR
Consider anti-D if Rh negative
(NB. Anti- D not required for CONFIRMED complete moles, but usually necessary as not confirmed till after histology available)
Management for future pregnancies
Women with history of partial/complete molar:
- they can start trying to conceive after they have completed BHCG follow-up
- early pregnancy USS and serum BHCG
- HCG 6 weeks after pregnancy to ensure it is negative (RANZCOG recommend, not RCOG)
Risk of change from partial or complete molar to malignant disease
0.5 – 4% of partial moles
15– 25% of complete moles.
Presentation of persistant GTD
Persistent GTD usually presents with βhCG elevation following a molar pregnancy, however clinical features can include PV bleeding, abdominal pain or swelling.
Rarely it can present with signs of metastases (e.g. haemoptysis or seizure due to pulmonary or cerebral mets)
Gestational choriocarcinoma
Gestational choriocarcinoma most commonly follows a complete molar pregnancy (25-50%), within 12 months of a non-molar abortion (25%), or after a term pregnancy (25-50%).
Symptoms may include PV bleeding, pelvic mass, or symptoms from distant metastases such as liver, lung and brain metastases.
HCG is always elevated.
It may be a difficult pathological diagnosis because of the frequent haemorrhage and necrosis that accompany it.
This is a tumour that crosses the placenta so the newborn of a mother newly diagnosed with
choriocarcinoma must be investigated to exclude disease (urinary Bhcg)
Placental site trophoblastic tumour
Placental Site Trophoblastic Tumour (PSTT) is very rare.
This frequently presents as a slow growing tumour a number of years after a molar pregnancy, non-molar abortion or term pregnancy.
Usually PSTT presents with gynaecologic symptoms, as metastases are later and rarer than in Choriocarcinoma.
Rarely, patients can present with hyperprolactinaemia or nephrotic syndrome.
Usually the hCG levels are relatively low in PSTT relative to the volume of the disease.
PSTT is increasingly thought of as a separate entity, as its behaviour differs from other GTDs.
PSTT should be considered in cases of relapse. Treatment for PSTT is usually hysterectomy.
Epithelioid trophoblastic tumour
Epithelioid Trophoblast Tumour (ETT) is a distinctive but rare form of GTN. It is a disease of intermediate trophoblast cells.
Pathological diagnosis is often difficult and differential diagnoses include Choriocarcinoma, PSTT and SCC of the cervix.
Histology specimens should be reviewed by specialist pathologists familiar with this condition. ETT is typically characterised by a long interval from the antecedent pregnancy and more commonly follows a term pregnancy.
βhCG levels are generally much lower than with a molar pregnancy. The biological behaviour of ETT is
less aggressive than choriocarcinoma, but its metastatic potential is similar to PSTT.
Primary treatment is hysterectomy as these tumours are resistant to chemotherapy. High mitotic index,
atypia and vascular invasion confer a poorer prognosis
Presentation of molar pregnancy in:
- 1st trimester
- Mid-trimester
Early pregnancy Ultrasound features PV bleeding Hyperemesis Abnormally high βhCG levels
Mid-trimester
Large for dates
Pre-eclampsia, hyperthyroidism, pulmonary
or neurological symptoms
Investigation for molar pregnancy
BHCG Pelvic USS Histology Request ancillary testing if indicated (ploidy, karyotype, p57) CXR Request MDT review if pathology unclear
Management of molar pregnancy once diagnosed
Suction evacuation of the uterus
Consider USS guidance to reduce risk perforation
All tissue for histology and ancilliary testing
Counsel patient:
Diagnosis
Follow-up as risk of persistent disease or transformation to malignancy
To avoid getting pregnant until BHCG follow-up completed - COCP is no longer thought to increase the risk of invasion/metastases
Risk of GTD recurrence after any future pregnancy
Referral should be made to GTD centre.
All blood tests should be ordered through same
Pathology provider, and follow-up by the same team.
Partial mole – after two consecutive normal
levels 1 month apart no further testing required (RCOG)- RANZCOG states x3
Complete mole – monthly for six months from
negative evacuation, RANZCOG- also 3x negative
Referral to gynae onc if any of the following:
Rise: Greater than 10% rise in βhCG value over two
weeks (i.e.; three consecutive results)
Plateau: Less than 10% fall in βhCG values over
three weeks (i.e. 4 consecutive results)
Elevated levels at 6 months
Signs of metastases
What information do you need to provide women regarding suspected or confirmed molar pregnancy?
At the time of diagnosis and ongoing monitoring:
Inform patient:
Diagnosis
Follow-up as risk of persistent disease
To avoid getting pregnant until advised
Risk of GTD after any future pregnancy
Counselling
After HCG follow up finished:
Inform both patient and GP:
Pregnancy is now a reasonable option
Fertility rate not affected
1:70 risk of repeat molar pregnancy, therefore
recommend early ultrasound, and βhCG level
6 weeks following the completion of any future
pregnancies (regardless of outcome of that
pregnancy) (although 2020 RCOG guideline states this is no longer necessary if the woman didn’t receive chemotherapy)
Persistent bleeding or rising HCG- recommendation re second evac from RANZCOG?
In selected cases, a second evacuation may be necessary because of problematic bleeding but it has been shown that there is still a 70% chance of requiring chemotherapy, and an 8 per cent chance of uterine
perforation.
If considering a second surgical evacuation, liaise with your local GTD registry. Consider hysteroscopy in order to locate persistent focus, if a second evacuation is performed.
Repeat evacuation is not recommended if βhCG >5000 or in the presence of metastases.
All products of conception obtained at evacuation for suspected GTN should be sent for histology.
Ploidy status and immunohistochemistry staining for P57 may be useful for differentiation between partial or complete mole.
