Gestational trophoblastic disease (GTD) forms a group of disorders spanning the conditions of complete andpartial molar pregnancies through to the malignant conditions of invasive mole, choriocarcinoma and the veryrare placental site trophoblastic tumour (PSTT). There are reports of neoplastic transformation of atypicalplacental site nodules to placental site trophoblastic tumour.If there is any evidence of persistence of GTD, most commonly defined as a persistent elevation of beta humanchorionic gonadotrophin (βhCG), the condition is referred to as gestational trophoblastic neoplasia (GTN).