From the archives of the AFIP. Gestational trophoblastic disease: radiologic-pathologic correlation.

Gestational trophoblastic disease (GTD) is a manifestation of an aberrant fertilization event that leads to a proliferative process and, potentially, to an invasive neoplasm. The spectrum of GTD includes hydatidiform moles (complete and partial), invasive mole, choriocarcinoma, and placental site trophoblastic disease (rare). Increased levels of human chorionic gonadotropin (beta-hCG) are associated with all forms. Ultrasonography (US), performed late in the first trimester of a pregnancy complicated by hyperemesis gravidarum, toxemia, or bleeding, is essential in the early detection of hydatidiform mole, the most common form of GTD (80% of cases). In these cases, US typically reveals a central heterogeneous mass with anechoic spaces, which correspond to hydropic villi. In cases of invasive mole, imaging may show a central uterine process (similar to that seen in noninvasive moles), occasionally with myometrial invasion. Choriocarcinoma is often seen as a mass enlarging the uterus, with a heterogeneity that correlates with necrosis and hemorrhage. Because of the widespread availability of serum measurement of beta-hCG, diagnosis of the more severe, persistent manifestations of GTD seldom depends on radiologic examinations. However, imaging studies may alert the referring physician to the diagnosis in cases of early disease. Also, imaging studies may have a problem-solving role in examining patients with recurrent GTD or a confusing clinical picture.