Gestational trophoblastic disease

Introduction Gestational trophoblastic disease (GTD) includes a spectrum of diseases with a wide range of neoplastic potential and is among the rare solid human malignancies that can be cured even when widely disseminated. Gestational trophoblastic neoplasia is a subtype that is nearly always maligant. Reasons for this success include a sensitive marker, human β-chorionic gonadotropin (hCG), and sensitivity to various chemotherapy agents and other modalities such as surgery and radiation. Although four distinct clinicopathological forms are recognized – complete or partial hydatidiform mole, invasive mole (chorioadenoma destruens), placental site trophoblastic tumor (PSTT), and choriocarcinoma – diagnosis and management can be based solely on history, elevated serum hCG, and metastatic workup. This approach, in which a disease is treated by cytotoxic drugs based on clinical classification without cytological or pathological documentation of malignancy, is unique. Hydatidiform mole Epidemiology The precise incidence of molar pregnancy is difficult to derive, because in most reports neither the total number of pregnancies nor the total number of hydatidiform moles in a defined population is known. The most reliable studies suggest that the incidence of hydatidiform mole is slightly less than 1 out of 1000 pregnancies in most of the world and possibly as high as 1 out of 500 pregnancies in East Asia and parts of Latin America.