gestational trophoblastic disease

Question 1

what are the 2 main types of gestational trophoblastic disease?

Answer 1

1. hydatiform moles

2. gestational trophoblastic neoplasias

Question 2

what is a hydatiform mole?

Answer 2

• a chromosomsally abnormal pregnancy which develops due to abnormal fertilisation

Question 3

what is the common presentation for GTD?

Answer 3

first trimester of pregnancy

• abnormally high BHCG
• causes hyperemisses
• vaginal bleeding
• uterus large for dates

BHCG can mimic TSH resulting in:
Tachycardia
Tremor
Sweating
Hypertension

theca leutean cyst can also form which can cause pain ad adnexal mass symptoms

Question 4

what are risk factors of GTD?

Answer 4

GTD is more common in Asia and Africa.
Extremes of reproductive age: < 16 years or > 45 years
Prior gestational trophoblastic disorder
Family history

Question 5

what are the 2 types of neoplastic GTD?

Answer 5

• invasive moles

- choriocarcinoma

Question 6

what are the 2 types of benign GTD?

Answer 6

• partial mole

- complete mole

Question 7

what is the pathophysiology of a particle mole?

Answer 7

• 2 sperm fertilise a single ovum leading to 69 chromosomes- fetal tissue is present
• risk of it turning into a neoplasia is 5%

Question 8

what is the pathophysiology of a complete mole?

Answer 8

• haploid sperm fertilises an empty oocyte, then duplicates its DNA- leading to 46 chromosomes- fetal tissue is absent
• risk of it Turing into neoplasia is 20%

Question 9

what’s the clinical difference between presentation of a complete vs incomplete mole?

Answer 9

incomplete secretes less HCG so less nausea and vomiting and less hyperthyroid symptoms

it won’t grow as fast as a complete mole- so less likely to have a uterus that is too big and you won’t have ovarian cysts

Question 10

what are likely results of GTD investigations?

Answer 10

• β-hCG: will be abnormally high in molar pregnancies (> 100,000 IU/L)
• TFTs: β-hCG may mimic TSH and cause thyrotoxicosis with a normal TSH
• Pelvic ultrasound: ‘snowstorm appearance’ in the second trimester
• Renal profile and liver function: abnormal in metastatic disease
• Histology: definitive diagnosis conducted on evacuated tissue
• Staging imaging: a CT chest, abdomen and pelvis is usually performed for choriocarcinoma

Question 11

what is the treatment for molar pregnancy?

Answer 11

Suction curettage: the preferred method of evacuation for both complete and partial moles. All samples should be sent for histology to exclude neoplasia

Anti-D prophylaxis: required for patients following evacuation
β-hCG is monitored regularly post-evacuation until it has normalised; failure to normalise suggests recurrence

Question 12

what is the treatment for gestational trophoblastic neoplasia?

Answer 12

Chemotherapy: intramuscular methotrexate alone (low-risk)

or with other agents, such as dactinomycin (high-risk or metastatic)

Question 13

what are complications of GTD?

Answer 13

• Malignant transformation: benign moles may transform into gestational trophoblastic neoplasia (invasive mole or choriocarcinoma).
• The lungs are the most common site of metastasis
• Asherman’s syndrome: secondary to curettage which causes uterine adhesions, potentially resulting in amenorrhoea
• Pre-eclampsia: may reflect advanced disease.