Pathology of gestational trophoblastic neoplasia: a review with recent insights

Abstract

Gestational trophoblastic neoplasia (GTN) refers to a unique and heterogeneous group of conditions demonstrating differentiation towards various components of gestational trophoblast. Variants of hydatidiform mole (HM) are considered benign, whilst choriocarcinoma (CC), placental site trophoblastic tumour (PSTT) and the more recently described epithelioid trophoblastic tumour (ETT), a variant of PSTT, are malignant gestational trophoblastic tumours (GTT). The early and reproducible pathologic diagnosis of the various forms of GTN has been aided by recent developments in tumour markers, laboratory technology and new insights into our understanding of these different gestational diseases. Whilst CC is usually exquisitely chemosensitive, the much rarer PSTT and ETT require primary surgical management for optimal outcome. This dichotomous approach to the management of malignant GTT, determined by FIGO stage and differing tumour biology based on histology, has ensured an overall cure rate in excess of 90% for this group of tumours.