Gestational Trophoblastic Disease: Hydratidiform Mol

Question 1

Define

Answer 1

A benign tumour of the trophoblastic tissue

Aetiology – abnormal fertilisation leading to a ‘mole’ formation which is either…

Complete = empty egg fertilised by 2 sperm (or 1 which duplicates DNA)

• 46 XY or 46 XX (paternal origin only)

**Partial **= normal egg fertilised by 2 sperm (or 1 which duplicates DNA)

• 69 XXX or 69 XXY (1x maternal and 2x paternal origin)

Risk factors:
1. Extremes of reproductive age
2. Ethnicity (Japanese, Asians, native American Indian)
3. Previous GTD
4. Diet (low beta-carotene, low saturated fat)

Question 2

Signs and symptoms

Answer 2

Signs & symptoms:

• Painless PV bleeding (i.e. miscarriage)
• Hyperemesis (increased βHCG)
• Symptoms of hyperthyroidism rare (from high bHCG mimicking TSH)
• Often seen on USS before symptoms
• Uterus larger than expected for GA

Question 3

Investigations

Answer 3

Bloods – βHCG grossly elevated à b-hCG similar to TSH à low TSH, high T4

• Imaging – pelvic USS:
• Complete mole = snowstorm / ‘cluster of grapes’, no foetal parts

-Incomplete mole = no snowstorm / ‘cluster of grapes’, foetal parts

Question 4

Management

Answer 4

urgent referral to specialist centre…

• 1st -> Surgical – ERPC (Evacuation of Retained Products of Contraception) – NO contractions (disseminate it)

then… monitoring – serial βHCG monitoring in specialist centre – methotrexate if rising or stagnant levels, avoid pregnancy until 6 months of normal levels (bHCG will be VERY high for the gestation)

• Do not conceive until follow-up is complete (barrier and COCP)
• Avoid IUDs until hCG normalised
• If continues to rise -> ? choriocarcinoma

Question 5

Complications

Answer 5

→ can progress to malignancy (20% of complex moles, 2% of partial moles)

o Complete mole -> invasive mole = 10%; choriocarcinoma = 2.5%

o Partial mole -> choriocarcinoma = 0%

o Recurrence risk of 1% (≥2 molar pregnancies -> recurrence risk 17%)

Question 6

PACES

Answer 6

BREAKING BAD NEWS:

o Risk Factors:
- Advanced maternal age (or younger than 20)
- Prior molar pregnancy (1-2% risk of recurrence)
- Prior miscarriages
- Asian heritage

o Explain diagnosis (when foetus doesn’t form properly, and a baby doesn’t develop, instead there is an irregular mass of pregnancy tissue)

o Explain risks (can invade and damage other tissues)

o Explain immediate management (suction curettage)

o Explain follow-up (referral to trophoblastic screening centre to monitor pregnancy hormone levels)

• Molar pregnancy does NOT affect fertility (but there is a 1 in 80 chance of recurrence)
• Do NOT try to get pregnant until after follow-up is complete (~12m)

o Explain that further treatment may be necessary