Gestational Trophoblastic Disease

Question 1

What are the types of gestational trophoblastic disease?

Answer 1

Question 2

Define Hydatidiform Mole.

Answer 2

A benign tumour of the trophoblastic tissue.

Question 3

What is the aetiology of hydatidiform mole?

Answer 3

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)

Question 4

What are the risk factors for hydatidiform mole?

Answer 4

• Extremes of reproductive age
• Ethnicity - Japanese, Asians, native American Indian
• Previous GTD
• Diet - low beta-carotene, low saturated fat

Question 5

What are the signs and symptoms of hydatidiform mole?

Answer 5

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

Question 6

What are the appropriate investigations for suspected hydatidiform mole?

Answer 6

• Bloods
  
  • βHCG grossly elevated
  • b-hCG similar to TSH → 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 are shown

Question 7

What is the management of a hydatidiform mole?

Answer 7

• 1st = Surgical = ERPC (Evacuation of Retained Products of Contraception)
• Followed by Monitoring = Serial βHCG monitoring in specialist centre
  
  • Methotrexate if rising or stagnant levels
• Avoid pregnancy until 6 months of normal levels - give barrier and COCP but avoid IUDs until hCG normalised

Question 8

What should be considered if hCG continues to rise after treatment for a suspected hydatidiform mole?

Answer 8

Choriocarcinoma

Question 9

What are the complications of a hydatidiform mole?

Answer 9

• Can progress to malignancy - 20% of complex moles and 2% of partial moles
  
  • Complete mole → invasive mole = 10% - choriocarcinoma = 2.5%
  • Partial mole → choriocarcinoma = 0%
• Recurrence risk of 1% - ≥2 molar pregnancies = 17%

Question 10

What counselling should be given to women with hydatidiform mole?

Answer 10

• Be sensitive/Breaking bad news
• Explain the risk factors
  
  • Extremities of maternal age
  • Prior molar pregnancy
  • Prior miscarriages
  • Asian heritage
• Explain diagnosis - When foetus doesn’t form properly, and a baby doesn’t develop, instead there is an irregular mass of pregnancy tissue
• Explain risks - can invade and damage other tissues
• Explain immediate management - suction curettage
• Explain follow-up - referral to trophoblastic screening centre to monitor pregnancy hormone levels
• Explain that molar pregnancy doesn’t affect fertility
  
  • Don’t try to get pregnant until after follow-up is complete
• Explain that further treatment may be necessary

Question 11

What are the forms of gestation trophoblastic malignancy?

Answer 11

• Invasive mole → hydatidiform mole with invasion of myometrium, necrosis and haemorrhage
• Choriocarcinoma → cytotrophoblast and syncytiotrophoblast without formed chorionic villi invade myometrium
  
  • Rapidly metastasise
• Placental site trophoblastic tumour → intermediate trophoblasts infiltrate myometrium without causing destruction, contains GPL - very rare

Question 12

What are the risk factors for gestational trophoblastic malignancy?

Answer 12

• Extremes of reproductive age
• Ethnicity - Japanese, Asian, native American Indians
• Previous Gestational trophoblastic disease
• Diet – low beta carotene, low saturated fat

Question 13

What is the aetiology of gestational trophoblastic malignancy?

Answer 13

• Abnormal chromosomal material of placental tissue
• Invasive moles always follow hydatidiform mole

Question 14

What can form into gestational trophoblastic choriocarcinoma after?

Answer 14

• Molar pregnancy (50%)
• Miscarriage (25%)
• Viable pregnancy (22%)
• Ectopic pregnancy (3%)

Question 15

What are the signs and symptoms of gestational trophoblastic malignancy?

Answer 15

• O/E → excessive uterine size for gestation
• Persistent PV bleeding
• Hyperemesis gravidarum
• Lower abdominal pain
• Lung metastasis – haemoptysis, dyspnoea, pleuritic pain
• Bladder/bowel metastasis – haematuria, PR bleeding

Question 16

What are the investigations for suspected gestational trophoblastic malignancy?

Answer 16

• Bloods
  
  • Serum βHCG (persistently raised or rising after ERPC)
  • FBC
  • LFT - mets
• Imaging
  
  • Pelvic USS - snowstorm, vesicles or cysts
  • CXR, CT CAP, MRI brain - mets

Question 17

What is the management of gestational trophoblastic malignancy?

Answer 17

• Manage in specialist centres - CX, Sheffield, Dundee
• Chemotherapy - Methotrexate
• Hysterectomy for placental site trophoblastic tumour

Question 18

What are the complications for gestational trophoblastic malignancy?

Answer 18

• Metastasis
• Chemotherapy side effects