Gestational trophoblastic disease

Question 1

What is gestational trophoblastic disease

Answer 1

Term used to describe a group of pregnancy related tumours

Question 2

What are the two main groups of gestational trophoblastic disease

Answer 2

Pre-malignant

Malignant

Question 3

List some pre-malignant conditions

Answer 3

Partial molar pregnancy

Complete molar pregnancy

Question 4

List some malignant conditions

Answer 4

Invasive mole
Choriocarcinoma
Placental trophoblastic site tumour
Epithelioid trophoblastic tumour

Question 5

What does a molar pregnancy arise from?

Answer 5

Abnormality in chromosomal number during fertilisation

Question 6

What is a partial molar pregnancy?

Answer 6

Where one ovum with 23 chromosomes is fertilised by two sperm, each with 23 chromosomes
This produces cells with 69 chromosomes

Question 7

What is a complete molar pregnancy

Answer 7

Where one ovum without any chromsomes is fertilised by one sperm which duplicates or two different sperm. This leads to 46 chromosomes of paternal origin alone

Question 8

What are invasive moles?

Answer 8

Where molar pregnancies become malignant and invade into the myometrium before disseminating around the body

Question 9

What is a choriocarcinoma?

Answer 9

Malignancy of trophoblastic cells of the placenta

Commonly co-exists with a molar pregnancy

Question 10

Where does choriocarcinoma commonly metastasise to?

Answer 10

Lungs

Question 11

What is a placental site trophoblastic tumour

Answer 11

A malignancy of the intermediate trophoblasts which are normally responsible for anchoring the placenta to the uterus - can occur after a normal pregnancy, molar pregnancy or miscarriage

Question 12

What is an epithelioid trophoblastic tumour?

Answer 12

Malignancy of the trophoblastic placental cells which can be difficult to distinguish from choriocarcinoma - mimics the cytological features of squamous cell carcinoma

Question 13

List the risk factors for gestational trophoblastic disease

Answer 13

Maternal age <20 and >35
Previous gestational trophoblastic disease
Previous miscarriage
Use of oral contraceptive pill

Question 14

What are the clinical features of gestational trophoblastic disease

Answer 14

Vaginal bleeding 
Abdominal pain in early pregnancy
Hyperemesis  
Hyperthryoidism 
Anaemia

Question 15

What signs of gestational trophoblastic disease are there on examination?

Answer 15

Uterus larger than expected for gestation and of a soft, body consistency
Molar vesicles shed per vagina
Hyperthyroidism
Anaemia

Question 16

Why is hyperemesis present in gestational trophoblastic disease?

Answer 16

Increased titre of bHCG

Question 17

What investigations would you do for GTD?

Answer 17

Urine b-hCG
Blood b-hCG
USS
Histological examination of products of conception post treatment of molar/non-viable pregnancies
CTCAP, MRI where metastatic spread suspected

Question 18

Describe the appearance of a complete mole on ultrasound

Answer 18

Granular/snowstorm appearance with a central heterogenous mass and surrounding multipl cystic areas/vesicles

Question 19

Describe the management of GTD

Answer 19

Register woman with a GTD centre for follow up and monitoring

Molar pregnancy - suction curettage

Partial mole - medical evacuation with urinary b-HCG 3 weeks post treatment

In all cases anti-D prophylaxis post evacuation if mother Rh negative

Chemotherapy after evacuation if B-HCG does not fall

Other GTD- single or multiple agent chemotherapy +/- surgery