"Bunch of grapes" in complete hydatidiform mole.

Complete hydatidiform mole is a common cause of gestational bleeding of the first trimester, commonly assessed by ultrasound. It represents an abnormal proliferation of trophoblastic tissue, with no fetal formation, just hydropic villi. These abnormal villi seen in ultrasound are compared to a "bunch of grapes," a classic description of this disease.