Placental site trophoblastic tumour mimicking an intramural pregnancy: a case report and review of the literature.

Gestational trophoblastic disease (GTD) covers a range of proliferative disorders from non-neoplastic hydatid moles to malignant neoplastic conditions such as choriocarcinoma. The incidence of these diseases is low and often challenging to diagnose. Placental site trophoblastic tumour (PSTT) is the rarest form of GTD, accounting for up to 3% of all cases.