Final answer:
Hydatidiform mole is characterized by abnormal uterine size growth caused by a mass of abnormal cells.
Step-by-step explanation:
Hydatidiform mole, a gestational trophoblastic disease, is characterized by abnormal uterine size growth. Unlike a normal pregnancy where the uterus grows steadily, in a hydatidiform mole, the uterus grows at an abnormal rate. This is because the mole is a mass of abnormal cells that forms instead of a healthy fetus. It is important to seek medical attention if a hydatidiform mole is suspected, as it can cause complications and requires treatment.