This case describes an atypical presentation of molar pregnancy in an emergency department patient with abdominal pain and vaginal bleeding. The patient demonstrated clinical features of hydatidiform mole, including acute discharge of a large, grape-like vesicular mass, despite multiple negative urine pregnancy tests. These false-negative qualitative human chorionic gonadotropin assays were likely caused by the "high-dose hook effect" and may have delayed proper care of the patient, who displayed pulmonary choriocarcinoma at the time of diagnosis.