Early pregnancy: Gestational Trophoblastic Disease Flashcards
What is gestational trophoblastic disease
pregnancy-related tumours
How can gestational trophoblastic disease be divided
- Pre-malignant conditions
2. Malignant conditions
What is pre-malignant gestational trophoblastic disease
Partial and complete molar pregnancies
What are malignant gestational trophoblastic disease
Choriocarcinoma, Invasive mole,
Explain chromosomes in normal fertilisation
Normally 23 from mother and 23 from father
What causes a molar pregnancy
Abnormality in foetal chromosomes
What is a partial molar pregnancy
There is one ova (23 chromosomes) fertilised by two sperm (each 23 sperm). Gives 69 chromosomes in total = triploidy.
What is a complete molar pregnancy
One ova (with 0 chromosomes) is fertilised by one sperm which then duplicates. Giving 46 chromosomes all male in origin.
What are partial and complete molar pregnancies called
Hydratidiform moles
What are invasive moles
Usually benign, but can become malignant by invading myometrium.
What is a choriocarcinoma
Malignancy of trophoblastic cells
What does choriocarcinoma often originate from
molar pregnancy
What metastses are common in choriocarcinoma
Lung
What are hydratidiform mole
tumours arise from proliferating chorion that has swollen and degenerated
What are the two types of hydratidiform mole
- Complete mole
2. Partial mole
How does complete hydratidiform mole present
Hydropic villi
What causes complete hydratidiform mole
One ova with 0 chromosomes is fertilised by one sperm, whose chromosomes then duplicated. Giving total 46 chromosomes, but they are all paternal
How does a partial hydratidiform mole present
Normal and hydropic villi
What causes a partial mole
One ova with 23 chromosomes is fertilised by two sperm (23 chromosomes) giving 69 chromosomes = triploidy
What are 5 risk factors for hydratidiform mole
- <15 and >45
- Asian
- Previous gestational trophoblast disease (even if different partner)
- previous miscarriage
- COCP
How does hydratidiform mole present clinically
- Irregular bleeding in first trimester (90%)
- Uterus large for dates
- Pain = due to bHCG causing enlargement theca cysts
- Exaggerated symptoms pregnancy = due to bHCG
Where are hydratidiform mole derived from and what does this cause
Chorion - excess bHCG secretion
What is used as a investigation for hydratidiform mole
bHCG = markedly raised out of proportion to gestation age
What is second-line investigation for hydratidiform mole
Transvaginal US
How does complete hydratidiform mole present on transvaginal US
Snowstorm appearance - due to echogenic mass with hypoecogenic cystic spaces
How may partial hydratidiform mole present
Foetus may be visible.
IUGR
Thickened placenta
What is required to confirm diagnosis of hydratidiform mole
Histological diagnosis of products of conception
How are complete hydratidiform moles managed
Surgical evacuation and oxytocin to control haemorrhage
How are partial hydratidiform moles managed
Surgical evacuation
Define choriocarcinoma
Malignancy of chorio and synctiotrophoblasts
When can choriocarcinomas only develop
only after ova has been fertilised and implanted
What precedes 50% of choriocarciomas
hydratidiform mole
What is the most common sign of choriocarcinoma
failure of uterus to regress following delivery
What is a symptom of choriocarcinoma
post-partum bleeding
What is the most common site of metastses of choriocarcinoma
lungs
How is choriocarcinoma managed
chemotherapy
