Gestational trophoblastic disease is a spectrum of conditions arising from abnormal placental tissue growth after conception. The most common form is a hydatidiform mole, or molar pregnancy, in which the placental tissue grows excessively and abnormally. On ultrasound, a complete molar pregnancy has a classic snowstorm appearance with numerous small, echogenic cystic spaces filling the uterus without a visible fetus, while a partial mole may show a fetus with an abnormal, enlarged placenta containing cystic spaces. Early ultrasound detection is important because molar pregnancies require prompt treatment with uterine evacuation, and a small percentage can develop into gestational trophoblastic neoplasia, a treatable form of cancer.
Sonography Term