Gestational trophoblastic disease

Question 1

GTD - overview

Answer 1

• Group of tumours that arise from the fetal trophoblast
• It is an essential characteristic of normal human trophoblast to invade the endometrium and maternal blood vessels
• Usually this invasive behaviour is limited, but in trophoblastic tumours, there are abnormally proliferating trophoblasts capable of unlimited growth, invasion and in some cases, metastatic spread
• May be benign (hydatidiform mole) or more rarely, malignant (gestational trophoblastic neoplasia - invasive mole, placental site trophoblastic tumour and choriocarcinoma)

Question 2

GTD - key features

Answer 2

1. Occur in association with a pregnancy (ranging from early pregnancy loss to full-term normal pregnancy)
2. Tumour DNA always differs from pt’s own DNA
3. hCG produced by the trophoblast is an excellent tumour marker, allowing reliable dx and mx
4. Very sensitive to chemotherapy -> nearly 100% cure rate, often without loss of reproductive function
5. Rare

Question 3

Complete mole - overview and presentation (path/hx/ex/ix)

Answer 3

1. Diffuse hydropic villi with trophoblastic hyperplasia
2. Diploid, derived from sperm duplicating its own chromosome following fertilisation of an ‘empty’ ovum. Mostly 46XX with no evidence of fetal tissue

Question 4

Partial mole - overview

Answer 4

1. Consists of hydropic (?) and normal villi
2. Triploid (69XXX, XXY, XYY) with one maternal and two paternal haploid sets; most cases occur following two sperms fertilising an ovum, and a fetus may be present

Question 5

Hydatidifom mole - symptoms and signs

Answer 5

1. Irregular first-trimester vaginal bleeding
2. Uterus large for dates
3. Pain from large theca lutein cysts resulting from ovarian hyperstimulation by high hCG levels
4. Vaginal passage of vesicles containing products of conception
5. Exaggerated pregnancy symptoms - hyperemesis, hyperthyroidism, early pre-eclampsia

Note - serum hCG is excessively high with complete moles, but levels may be within normal range for partial moles

Question 6

Hydatidiform mole - risk factors (3)

Answer 6

1. Age - extremes of reproductive life (>40y or

Question 7

Hydatidiform mole - mx

Answer 7

1. Suction curettage
2. Concomitant U/S examination, oxytocic support and careful cervical dilatation to avoid perforation of the very soft uterus. Note - haemorrhage at the time of curettage is an important risk and must be managed promptly
3. Anti-D immunoglobulin should be administered to Rh-negative women
4. Careful follow-up by hCG tracking to detect gestational trophoblastic neoplasia. Weekly hCG assays until two consecutive negative results have been obtained, followed by monthly assays for 6mo in the case of complete molar pregnancy
5. Use reliable contraception during this time to ensure that f/u is not complicated by a new pregnancy (COCP or progestogen based contraceptive)

Question 8

Gestational trophoblastic neoplasia - background

Answer 8

1. S