Gestational trophoblastic disease encompasses a broad spectrum of conditions, includes hydatidiform mole, invasive mole, choriocarcinoma, and placental site trophoblastic tumor. Although sonography is the examination of choice for the initial diagnosis, MR imaging has a role in the detection of gestational trophoblastic disease and the evaluation of the extent of its complications. Relative to US and CT, MR imaging may demonstrate the tumor,myometrial invasion, and extension into the parametrium clearly with excellent soft-tissue contrast
Hydatidiform Mole
Hydatidiform mole constitutes 80% of cases of gestational trophoblastic disease. Hydatidiform mole usually appears as a heterogeneous markedly hyperintense mass on T2-weighted images that distends the endometrialcavity. On contrast-enhanced T1-weighted images, characteristic numerous cystic areas are clearly seen in the mass. The normal myometrium remains and surrounds the mass.
Hydatidiform mole constitutes 80% of cases of gestational trophoblastic disease. Hydatidiform mole usually appears as a heterogeneous markedly hyperintense mass on T2-weighted images that distends the endometrialcavity. On contrast-enhanced T1-weighted images, characteristic numerous cystic areas are clearly seen in the mass. The normal myometrium remains and surrounds the mass.
Invasive Mole
An invasive mole develops in approximately 10% of patients after molar evacuation and infrequently after other gestations. This form is defined as a mole that penetrates and may even perforate the uterine wall. There is invasion of the myometrium by hydropic chorionic villi, accompanied by proliferation of trophoblast. The tumor is locally destructive and may invade parametrial tissue and blood vessels.
An invasive mole develops in approximately 10% of patients after molar evacuation and infrequently after other gestations. This form is defined as a mole that penetrates and may even perforate the uterine wall. There is invasion of the myometrium by hydropic chorionic villi, accompanied by proliferation of trophoblast. The tumor is locally destructive and may invade parametrial tissue and blood vessels.
An invasive mole appears as a poorly defined mass displaying mixed signal intensity on T2-weighted images and deeply invades the myometrium. Complete or partial disruption of the junctional zone may also be seen. On T1-weighted images, the mass is isointense to the myometrium with scattered foci of high signal intensity because of the presence of hemorrhage. Molar like structures appear as tiny cystic lesions within the well-enhanced zone of trophoblastic proliferation in a mass of the invasive mole. With the penetration of the tumor into the myometrium, the invasive mole appears as a more aggressive entity than does choriocarcinoma
Choriocarcinoma
Approximately 5% of cases of hydatidiform mole are followed by choriocarcinoma. T1-weighted images show isointense or hyperintense masses. On T2-weighted images, the masses have various signal intensities, depending on the length of time the patient has had the hemorrhage. After gadolinium administration, the tumors appear as heterogeneous masses with necrotic centers. The enhancing solid component is usually located in the periphery of the mass. Intratumoral vascularity is minimal in most patients with choriocarcinoma compared with the vascularity of invasive mole tumors.
Approximately 5% of cases of hydatidiform mole are followed by choriocarcinoma. T1-weighted images show isointense or hyperintense masses. On T2-weighted images, the masses have various signal intensities, depending on the length of time the patient has had the hemorrhage. After gadolinium administration, the tumors appear as heterogeneous masses with necrotic centers. The enhancing solid component is usually located in the periphery of the mass. Intratumoral vascularity is minimal in most patients with choriocarcinoma compared with the vascularity of invasive mole tumors.