Gestational Trophoblastic Disease (GTD)
This booklet is intended as a practical guide to patient care for registrars, medical officers, interns and medical students attached to the gynaecology units at the University of the Witwatersrand Academic Hospitals. Anyone can use it.
Discharging a patient after evacuation
Indications for referral for chemotherapy
Hydatidiform mole (complete & partial) is much more common than Choriocarcinoma. The rare Placental Site Trophoblastic tumour & Epithelioid Trophoblastic Tumour are not usually seen. Choriocarcinoma is the rare malignant form. Benign forms metastasize – they spread, parting & breaking tissues without true invasion except in the uterus.
Most patients with GTD present as an inevitable miscarriage, but it may occur after a normal pregnancy, a complete miscarriage or ectopic gestation. Rarely, there may be no clear history of current or past pregnancy.
HYDATIDIFORM MOLE
Diagnosis
- There may be passage of grape-like products from the vagina may be brought in by the patient, noticed on examination, or an ultrasound scan may show multiple intrauterine cysts of different sizes (the typical ‘snowstorm’ appearance was from scanners no longer in use) or first noticed at uterine evacuation.
- Histology is diagnostic
Investigations
- FBC, hCG level & thyroid function
- Chest X-ray (for metastases)
- Consider abdominal ultrasound or CT scan for liver, spleen & kidney metastases if hCG level >100 000 U/L.
- Sonar may show huge multi-septate theca lutein ovarian cysts – these are managed conservatively (unless torted, which is rare)
Pre-operative preparation
For cases recognized pre-evacuation, presenting as incomplete/threatened miscarriages
- If Hb <9 g/dL, give 2 units packed cells pre-operatively
- Order 2 units packed cells on standby in a blood box for theatre
- Softening the cervix is not usually required pre-op. Avoid misoprostol or E2 preparations to ripen the cervix as they may cause excessive preoperative bleeding
Uterine evacuation
- Should be done by a registrar or consultant
- Use a suction curette
- Place the curette just inside the uterus with the tip in the lower pole. As suction begins the uterus will contract down towards the suction catheter. Gentle scraping with a large curette confirms an empty cavity
- Oxytocin infusion 10-20 units in 1 L to encourage uterine contraction
- If bleeding persists give ergometrine 0.5 mg IM or Syntometrine 1 amp IM at the end of the procedure
- There is a debate that if the uterine size at presentation is >20weeks hysterectomy rather than evac might be indicated. Seek local advice
Partial mole
In partial mole, there is an abnormal fetus. Compared with complete hydatidiform moles, partial moles tend to occur in older patients & are less likely to complicate with malignancy, hyperthyroidism or theca lutein cysts. Management is however the same. Absence of a fetus on ultrasound does not exclude partial mole as the fetus may have been passed unnoticed.
Theca lutein cysts
Large bilateral multicystic ovaries may be found in association with hydatidiform mole. Bleeding and torsion have been reported but are rare. In general, allow the cysts to regress even if they are very large.
Metastases
Metastases are rare with hydatidiform mole but do occur. Do not biopsy suspected vaginal metastases in the vagina as they bleed profusely. Lung metastases seen on chest X-ray do not require biopsy. As above, CT evaluation for metastases may be indicated. This may include head CT.
Discharging a patient after evacuation
- Encourage, encourage, encourage the patient to attend regularly for follow-up
- Stress that the diagnosis must still be confirmed by histology
- Ensure effective contraception is provided or sought (combined pill or injectable)
Follow-up visits
First obtain histology & hCG results. International studies show that if you ask someone with little finance to come excessively often they will default.
- See the patient every 2 weeks until hCG levels are below 25 Units/L
- Then see the patient monthly for one year after evacuation. Pregnancy must be avoided at this time as hCG is the marker & of course associated with normal pregnancy. A rise may make termination necessary, & a pregnancy may worsen persisting molar disease. A terminated pregnancy may be normal
- At each visit:
- A consultant should be informed & supervise management
- Ask about general well-being & irregular vaginal bleeding
- Confirm that the patient is taking contraception
- If hCG levels are persistently raised but stable for several weeks there may be a subsequent drop to normal. This is the ‘plateau’ effect. With static levels & a closed cervix and no persistent bleeding, observe for 3-4 weeks before investigation or referral for chemotherapy
- Re-evacuate for persistent bleeding with an open cervix & retained products on ultrasound
- Invasive mole on ultrasound, persistent high hCG levels & a completed family is a potential indication for hysterectomy rather than referral for chemotherapy. HCG follow up is still essential.
Indications for referral for chemotherapy
- Multiple high risk factors at the time of diagnosis (consult oncology protocols).
- HCG levels not falling (consider re-evacuation if ultrasound shows retained products).
- Metastases discovered at any time during work up. FIGO staging (v simple) should be given
- Choriocarcinoma on histology
FIGO Staging: 1 – uterus, 2 – pelvis, 3 – lungs, 4 – other organs. Scoring (with a rating of 0-3): age, preceding pregnancy, time since pregnancy, hCG level, tumour size, site & number of mets. 6 or less single agent chemo, 7 or more multiple.