Module 13 - Gestational Trophoblasic Disease Flashcards
GTG 38
What is the overall incidence of GTD?
1:714 pregnancies
(But <1:500 if <15 years
and 1:8 if >50 years).
GTD is pre-malignant. What conditions does this group include?
Complete molar
Incomplete molar
What is the pathophysiology of complete molar pregnancies?
DIPLOID
75% - sperm duplication in empty egg. 25% - 2 sperm in one egg.
What is the pathophysiology of partial molar pregnancies?
TRIPLOID
90% 2 sperm in 1 egg.
What differentiates complete from partial molar?
Complete - no foetal parts.
Partial has Foetal RBCs or feotal parts.
What are the clinical signs of GTD?
Irregular PVB
+UPT
very raised bHCG
US evidence
Enlarged uterus
What proportion of GTN present with irregular PVB?
60%
What is the sensitivity and PPV of US in complete molar pregnancies?
95% sensitivity
40% PPV
What are the US features are complete molar pregnancy?
5-7/40: polypoid mass
>8/40: thickened cystic appearance of villous tissue and no gestational sac (BUNCH OF GRAPES).
What is the sensitivity and PPV of US for partial molar?
Sensitivity 20%
PPV 20%
(but 40% if soft markers are also used).
What are the US features consistent with a partial molar pregnnacy?
Enlarged placenta.
Cystic changes in decidual reaction.
Empty sac.
Foetal RBCs or foetal parts.
>1:1.5 transverse to AP ratio of cystic spaces in placenta.
Do GTD patients need anti D after removal of pregnancy tissue?
Complete - no as there is no trophoblasic tissue.
Patial - yes. Give if suspected if hysto will take >72 hours.
Is cervical preparation safe pre SMM in GTD?
Yes.
What is the risk of retained POC after D&C vs MMM for GTD?
1% D&C
16% MMM
Are oxytotics safe after treatment for GTD?
NO!
Risk of systemic GTD spread via vascular system.
When should D&C be repeated after GTD treatment?
Represent with PVB and instability.
HCG<5000 (as 40% then avoid chemo).
What proportion of GTN is NOT recognised pre removal?
3%
When is histology required?
After all medical or surgical procedures if no foetal parts seen on USS (inc pole).
(except TOP).
Some women have fmailial high bHCG. What range would this expected to be in?
10 - 200
(regular cycles and can conceive)
What are the differentials for persistently mildly raised bHCG?
- Germ cell tumours
- Epithelial tumours (inc breast, bladder, lung, liver and colorectal)
- Pituitary hCG
- human anti-mouse antibodies.
HCG tests detect what types of HCG?
- Intact bHCG subunit
- Free bHCG subunit
- Nicked HCG
- hCG (b core) fragment.
Why is there a worse prognosis if women are found to have GTN after a non molar pregnancy?
Present later
More advanced and more likely mets.
What is the risk of GTN if bHCG normal at 8/52?
<1%
Should vaginal lesions be biopsied if women present with irregular bleeding after non-molar pregnancy?
NO
Risk of major haemorrhage
leave them alone, could be GTN deposits.
What FU is recommended for complete molar?
If bHCG normalised in >56 days, then FU for 6 months after tissue removal.
If bHCG normalised >56 days then FU for 6 months after bHCG normalised.
What FU is recommended for partial molar?
Can stop follow up once 2 normal bHCGs 4 weeks apart.
Ectopic molar tissue can be confused what?
How should this be managed?
Choriocarcinoma
Manage as per ectopics.
What are the risks of:
1. fetal demise
2. PTL
3. PET
if there is a viable twin with co- existing molar?
- 40% fetal demise
- 36% PTL
- 4 - 20% PET
In co-existing GTD/viable twins, what is the likely placental histology?
Mesenchymal hyperplasia.
What is the risk of needing chemotherapy after GTN vs co-existing twin?
GTD 15%
Co-existing twin 1%
What is the treatment for PSTT and ETT?
HYSTERECTOMY for local disease.
but intense chemo if mets or long time between pregnancy and diagnosis.
What are the types of GTN?
- Invasive mole
- Choriocarcinoma
- PSTT (placental site trophoblastic tumour)
- ETT (epithelioid trophoblastic tumour).
What is a PSN?
What are the 2 types?
Placental Site Nodule
Atypical and Typical types.
Is typical PSN concerning?
No, this is benign and relatively common. No FU needed.
Is atypical PSN concerning?
Yes. refer to GTD centre.
10-15% turn into PSTT or ETT.
Therefore need staging lap and hysterectomy.
How is atypical PSN often identified?
endometrial biopsy for irregular PVB.
What single dose chemotherapy agent is used to treat GTN?
Methotrexate.
What chemotherapies might be used in multi-agent chemotherapy?
(Platanum based).
Methotrexate.
Dactinomycin
Etopiside
Cyclophosphamide
Vincristine
What staging system is used for GTN?
FIGO 2000
What is a low risk score for GTN?
What is the cure rate?
What chemotherapy regime us used?
6 or less
100% cure rate
Single dose chemotherapy
What % of GTD is PSTT or ETT?
0.2%
but poor chemo response and likely lymph spread.
What is the best prognostic factor for PSTT and ETT?
Stage 4 - 100% death
Also : Time since ante-descent pregnancy
<48 months - nearly all survive
>48 months - 100% death.
How long after chemo treatment for GTN should a woman avoid conceiving?
1 year
(2% risk of teratogencity in that time and increased rate miscarriage)
After next pregnancy, do women need a post natal bHCG?
Yes if had chemotherapy for GTN.
No if did not have chemotherapy for GTN.
What is the risk of PTL in next pregnancy after GTD?
What is unusual about this risk?
25% risk
but ONLY in next pregnancy.
What is the risk of stillbirth of conceive <12 months after GTD treatment?
0-2%
What is the rate of successful future pregnancy after GTD treatment?
80% (for single and multi agent chemo)
Should post chemo AMH be used to evaluate ovarian reserve?
No, because this doesn’t reflect the woman’s ability to conceive.
Is it common for periods to stop during chemotherapy treatment?
Yes.
But generally return, unless intense high dose chemo then unlikely to regain ovarian function post treatment.
FIGO Scoring Table for GTN
TABLE
