6.3 - GTD - Gestational Trophoblastic Disease

Question 1

Define Gestational trophoblastic disease (GTD)

Answer 1

Spectrum of tumours relating to abnormal forms of pregnancy arising from trophoblasts (placental, the lack of these cause pre-eclampsia)

Question 2

Define Choriocarcinoma

Answer 2

Malignant tumour containing synctiotrophoblasts and cytotrophoblasts.

Question 3

What is the most common form of GTD?
Give its 2 types
What finding on ultrasound would allow you to distinguish between them?

Answer 3

Hydatiform Mole can be
Partial: 2 sperms fertilize same ovum leading to triploidy (69XXY) - May show early foetal development on US
Complete: 1 sperm duplicates within an empty ovum (46XX) - Theca Lutein Cysts

Question 4

What is the typical presentation of GTD/molar pregnancy

Answer 4

exaggerated pregnancy symptoms
1) Severe hyperemesis
2) PV bleeding
3) Early PET (visual disturbances, headache, oedema, RUQ/Epigastric pain)
4) Thyrotoxicosis (Palpitations, tremor, diaphoresis, heat intolerance)

Question 5

What examination finding are you expecting on exam (GTD/molar)

Answer 5

SFH > Gestational age

Question 6

What findings are expected on ultrasound of a molar pregnancy?

Answer 6

TVUS
1) Enlarged uterus
2) Cystic Structure - Snowstorm appearance/Grape-like US
3) Partial Hydatiform - Early foetus may develop

Question 7

What investigations will you conduct for molar pregnancy/GTD?

Answer 7

Labs:
beta hcg (extremely elevated if persistent GTD/Choriocarcinoma)
TFTs,
Rhesus (bleeding)

Imaging:
US showing Snowstorm appearance, enlarged uterus, early foetal development (if partial)
Complete will show Theca lutein cyst
CXR +/- CTTAP - rule out metastasis from choriocarcinoma

Question 8

How would you manage GTD?

Answer 8

Bleeding => give Anti-D
Suction Evacuation under GA
with followup weekly until beta hCG is undetectable, This is typically 6-8 months

Question 9

You perform suction evacuation on a suspected GTD/molar pregnancy. During followup, you notice beta hCG levels are not falling, but instead plateauing or rising. What does this mean?

Answer 9

This is called persistent GTD which is a group of conditions where beta hCG fails to return to normal levels. This is not the same as a malignancy but has a good chance of becoming that.

Question 10

What type of hydatiform mole is most likely to be persistent GTD

Answer 10

15% of complete moles are persistent. (remember C for C - choriocarcinoma).

Question 11

What is the benefit of ERPC rather than medical management of molar pregnancy?

Answer 11

Sample may be obtained for histology

Question 12

How is GTD diagnosed?

Answer 12

Retrospectively via histology once specimen is obtained via evacuation suction

Question 13

Is choriocarcinoma a type of GTD?

Answer 13

Yes, it is a malignant form of GTD

Question 14

How would you determine if the malignant GTD is low or high risk?

Answer 14

Low risk = small tumour, no metastasis, beta hCG <40,000, short interval between antecedant prgnancy and symptoms.
High risk = Large tumour, very high beta hCG (>40,000), long interval between antecedant pregnancy and symptoms, development of metastasis.

Question 15

How long is 1 “cycle” of methotrexate?

Answer 15

3 weeks

Question 16

How is persistent GTD treated (incl. Choriocarcinoma)

Answer 16

Referral to a specialized gynaecology oncology centre where the disease score is calculated to assess risk.

Low risk -> IM methotrexate 1mg/kg or 50mg/M^2 until beta hCG undetectable + 2 cycles after that (6 weeks)

High risk -> Chemotherapy (platinum) + MAC (methotrexate, actinomycin, cyclophosphamide)/EMA-COV

+ for both, offer contraception until 1 year after treatment is complete

If family complete: Offer hysterectomy

Question 17

How does beta hCG levels affect prognosis of malignant GTD?
Give 2 other factors that will influence prognosis

Answer 17

Malignant GTD has an extreme elevation of beta hCG
<40,000 is a good prognosis
>40,000 is a worse prognosis

Other factors include time since last pregnancy, metastasis, prior chemo needed (worse if yes), or whether the antecedant pregnancy reached term (worse if yes)

Question 18

What must you advise women who are about to undergo treatment for persistent GTD?

Answer 18

No pregnancy until 1 year after treatment is complete => provide contraception as needed

Question 19

State 3 ddx for abdominal swelling in the setting of obstetrics and gynaecology

Answer 19

Ovarian pathology
OHSS from ovulation induction
Choriocarcinoma presentaion

Other: Congestive HF/RHF, Liver failure

Question 20

Choriocarcinoma is a malignant tumour containing synctiotrophoblasts and cytotrophoblasts.
What do choriocarcinomas arise from? (list in order)

How do they present?

What are the 4 most common sites of metastasis?

How would you diagnose choriocarcinoma?

Answer 20

Choriocarcinomas may arise from any pregnancy. Most commonly from
1) complete hydatiform moles (50%)
2) Normal pregnancy (25%)
3) Miscarriage (20%)
4) Ectopic (5%)

Presentation:
1) PV bleed (as any tumour would)
2) Abdominal or vaginal swelling (similar to ovarian tumours and OHSS)
3) sx of metastasis (=> if lung hemoptysis and if brain, headache, visual disturbances, seizures, hemiparesis)

Metastasis: Pelvis, abdomen, lung, brain

Diagnosis: Extremely elevated beta hCG for gestational age +/- symptoms of metastasis as above

Question 21

A patient presents to you with severe hyperemesis and PV bleed extremely elevated beta hCG and a complete hydatiform mole is confirmed after the specimen is obtained from suction evacuation. Anti-D was given as the mother is Rh-ve. The patient returns after 2 weeks and the beta hCG levels have plateaued and complaining of abdominal and vaginal swelling.
What additional investigations would you perform to confirm choriocarcinoma.

What is the likely prognosis given only the information you have?

How would you manage this patient at this stage?

Answer 21

TVUS/pelvic US to reassess for any mass
CXR for lung metastasis
CT TAP for abdomen and pelvic metastasis

Prognosis is good in this case as the interval between the antecedent pregnancy and beginning of symptoms is short

The same way you would manage any persistent GTD.

1) Referral to a specialized gynaecology oncology centre where the disease score is calculated to assess risk.

2) Define risk:
Low risk -> IM methotrexate 1mg/kg or 50mg/M^2 until beta hCG undetectable + 2 cycles after that (6 weeks)

High risk -> Chemotherapy (platinum) + MAC (methotrexate, actinomycin, cyclophosphamide)/EMA-COV

+ for both, offer contraception until 1 year after treatment is complete

3) If family complete: Offer hysterectomy

Question 22

A patient presents with irregular vaginal bleeding 3 weeks after confirming her pregnancy at home with PV bleed. She is scared that she is having a miscarriage. When testing bloods, you note a major increase in human placental lactogen. What is the most likely diagnosis? What are the beta hCG levels expected to be?

Answer 22

Placenta-site triphoblastic tumour (very rare). Presents with irregular vaginal bleeding.
Low beta hCG but extremely high human placental lactogen (anti-insulin=> hyperglycemia?)