Gestational trophoblastic disease — structured SAQ (15 marks)

(a) Management of the complete mole (5 marks)

One mark for the procedure; one each for the three operative cautions; one for anti-D and registration. ^[1][7]

• Suction evacuation is the preferred method regardless of uterine size, ideally ultrasound-guided, with a large-bore cannula, by an experienced operator. State it by name — sharp curettage is not the answer.^[1]
• Caution one — no oxytocin until the evacuation is under way. Oxytocics given before suction can express trophoblast into the venous circulation and cause pulmonary trophoblastic embolisation and acute respiratory distress.^[1][9]
• Caution two — no medical induction and no hysterotomy. Both disseminate trophoblast; prostaglandin cervical priming is used with care only where needed.^[2][9]
• Caution three — send all tissue for histology so a mole is not missed and surveillance can begin; confirm the diagnosis with p57 immunohistochemistry where uncertain.^[2][7]
• Give anti-D, as this woman is Rh D negative — molar trophoblast carries paternal antigens. Register her with the trophoblast disease centre before discharge, and start hCG surveillance.^[7][9]

(b) hCG surveillance and the shortened follow-up evidence (4 marks)

One mark each, maximum four. ^[2][4]

• Serial serum hCG, weekly until normal, then at decreasing intervals; the duration varies with histological type and the rate of regression. State that contraception is mandatory throughout to avoid a new pregnancy resetting the hCG clock.^[2]
• The shortened follow-up evidence. Of 6701 women in one UK unit, 422 (6 per cent) developed persistent trophoblastic neoplasia, and 412 of those (98 per cent) presented within 6 months of evacuation — supporting 6 months of follow-up after spontaneous hCG normalisation.^[4]
• The hCG-at-6-months rule. A cohort of nearly 14 000 women found that fewer than 1 per cent had a persistently high hCG above 5 IU per litre at six months, and of those under surveillance 98 per cent normalised spontaneously without chemotherapy, with no deaths — so a falling hCG at six months can be watched rather than treated.^[5]
• After normalisation, neoplasia is rare — a meta-analysis put the incidence at 0.35 per cent after complete mole and 0.03 per cent after partial mole, supporting minimised follow-up.^[8]

(c) FIGO staging and the prognostic score (6 marks)

Two marks for staging (all four stages correct), two for the score components and cut-off, two for applying them to treatment. ^[2][3]

FIGO anatomical staging: ^[2]

• Stage I — disease confined to the uterine corpus.
• Stage II — extends to the adnexa or vagina, limited to the genital structures.
• Stage III — extends to the lungs, with or without genital tract involvement.
• Stage IV — all other metastatic sites.^[2]

The WHO prognostic score — eight variables, each scored 0, 1, 2 or 4: age, antecedent pregnancy, interval from the index pregnancy, pre-treatment hCG, largest tumour size, site of metastases, number of metastases, and previous failed chemotherapy. The stage and score are written together, for example Stage II:4.^[2][3] The 2026 FIGO revision removed the previous-chemotherapy row, leaving seven variables with revised size and hCG bands and the same 6-or-below versus 7-or-above cut-off.^[10]

The cut-off and its treatment implication. A score of 6 or below is low risk and treated with a single agent (methotrexate with folinic acid or actinomycin-D). A score of 7 or above is high risk and treated with multi-agent EMA-CO. This woman's plateau-then-rise over three consecutive weekly values meets the FIGO treatment criterion, and her score would determine single-agent versus multi-agent chemotherapy.^[2][6]