Bleeding in early pregnancy: Gestational trophoblastic disease

Question 1

GTD

Answer 1

Tumours that arise from products of conception
- Invasive vs non-invasive

Question 2

Types of GTD

Answer 2

Invasive (aka GTN)
- Invasive mole
- Choriocarcinoma
- Placental site trophoblastic tumour

Non-invasive
- Hydatidiform moles (partial vs complete)

Question 3

Risk factors of developing GTD

Answer 3

Extremes of maternal age
History of previous GTD

Question 4

Complete mole

Answer 4

Duplication of single haploid sperm following fertilization of empty ovum
-> Diploid
Absent fetal tissue
Karyotype: 46XX, 46XY

Question 5

Clinical features of complete mole

Answer 5

Due to high levels of circulating hCG:
- Abnormal vaginal bleeding (prune juice)
- Pre-eclampsia
- Hyperthyroidism
- Excessive N/V (hyperemesis gravidarum)
- Uterine size large than dates
- Enlarged ovarian cyst

PE: accordingly to ^

Question 6

Ultrasound findings of complete mole

Answer 6

Snowstorm appearance of endometrium
Multiple vesicles “cluster of grapes”
Enlarged ovarian cysts
Absent fetus

Question 7

Risk of progression for complete mole

Answer 7

15% risk of becoming invasive mole
4% risk of choriocarcinoma

Question 8

Partial mole

Answer 8

Dispermic fertilisation of an ovum
-> triploid
Present fetal tissue
Karyotype: 69XXY, 69XYY

*2 sets of paternal haploid genes + 1 set of maternal haploid gene

Question 9

Clinical features of partial mole

Answer 9

Presents as missed miscarriage or incomplete miscarriage

*U/S features corresponds accordingly ^

Question 10

Risk of progression for partial moles

Answer 10

2-4% risk of persistence
Rare for malignant transformation

Question 11

Management of molar pregnancy

Answer 11

• Suction curettage or
  Hysterectomy
• Send for histological examination

Question 12

Postop surveillance

Answer 12

• Weekly serum HCG until negative, then monthly for 6 months
• Advise patient for contraception until HCG levels revert to normal to not be confused with new pregnancy (COCP best option)
• Avoid IUCD until HCG levels revert to normal to reduce risk of uterine perforation
• Risk of further molar pregnancy is 1 in 80

Question 13

What HCG levels is suggestive of invasive mole post molar pregnancy

Answer 13

Persistent elevated beta-hCG levels after molar evacuation
- plateau or rising

Question 14

Gestational trophoblastic Neoplasm

Answer 14

• Can follow ANY gestational event**
• More likely to follow COMPLETE MOLE
• If GTN after a non-molar pregnancy: likely choriocarcinoma (most aggressive)
• 10x more likely after spontaneous miscarriage than term pregnancy
• Usually locally invasive and seldom metastatic (unless post non-molar pregnancy due to delayed diagnosis)

Question 15

Clinical features of GTN

Answer 15

Chorionic proliferation
- Uterine size larger than dates
- HCG > 100,000
- Ovarian cysts (theca lutein)
Prior gestational event
Prior hx of molar pregnancy

Systemic
- Neuro
- SCN
- Breast
- Abdomen
- Pelvic (large uterus, adnexal masses)
- Vagina
- METS to lungs, vagina (hematogenous spread)

Question 16

What is the mode of metastatic spread of GTN and to which organ(s)?

Answer 16

Hematogenous spread to lungs, vagina

Question 17

Is histological dx required before starting treatment for GTN?

Answer 17

No. Only cancer that does not require histological dx before starting treatment.

Question 18

HCG levels suggestive of GTN post molar pregnancy

Answer 18

1. Rise of HCG on 3 consecutive weekly measurements
2. Plateauing of HCG levels for 3 or more weeks
3. HCG levels remain elevated for 6 months or more

Question 19

Investigations to do for GTN

Answer 19

1. serial HCG levels
2. Ultrasound
3. CXR for lung mets

Question 21

Staging of GTN

Answer 21

Figo staging of GTN
I: Confined to uterine corpus
II: Adnexa, vagina
III: Lungs
IV: Outside of lungs, vagina or pelvis

Question 22

Treatment of GTN

Answer 22

1. Mainstay is chemotherapy
   - Methotrexate or D-actinomycin
   - Consider multiple agent chemotherapy
2. Hysterectomy

Question 23

Prognosis of GTN

Answer 23

Very good for most patients and can retain fertility

Question 24

Choriocarcinoma

Answer 24

somewhat an exception
- Most agressive GTN
- Commonly FIGO stage IV
- Chemotherapy with multiple agents

Question 25

Difference between invasive mole, choriocarcinoma VS placental site trophoblastic tumour

Answer 25

Invasive mole, choriocarcinoma:
- HIGH HCG, EARLY Dx

Placental site trophoblastic tumour:
- LOW HCG, LATE Dx

Question 26

Placental site trophoblastic tumour

Answer 26

• hCG levels not elevated (not a good marker)
• Usually indolent, slow-growing, mets only in the late stages
• Not chemosensitive
• Requires hysterectomy as mainstay of treatment

Question 27

Investigations for GTD

Answer 27

• Vitals (BP - Pre-eclampsia, RR, HR, SpO2)
• FBC to check Hb
• GXM
• Blood group + Rh status for anti-D prophylaxis
  *Give RhoGAM to partial moles only bc it has fetal parts (Complete has no fetal parts)
• UECr TRO electrolyte disturbances especially if N&V
• TFT even if patient asymptomatic due to risk of intra-op thyroid storm (Molar pregnancy-indued hyperthyroidism/ thyrotoxicosis)
• Beta-hCG levels preop and postop for f/u (Tumor marker)