Solution: Gestational trophoblastic disease is a spectrum of diseases all of which arise with an initial fertilization, but represent very abnormal trophoblastic and they include: Partial Mole, Invasive Mole, and Choriocarcinoma (1-2% of cases and distinguished by metastases). Classic appearance on US is described as an endometrial mass that has a "snowstorm" appearance, but can be more heterogeneous and is often very hypervascular. In 25-65% of cases (as in this case) there are associated theca-lutein cysts, driven by the very high beta-HCG levels. Clinically, the typical history is hyperemesis gravidum in a patient measuring too large for dates and can be associated with beta-HCG levels into the 100's of thousands. It is important to evaluate for invasion of the myometrium, or evidence of metastatic disease. Choriocarcinoma is treated with chemotherapy and rarely hysterectomy. It has an ~90% cure rate.