Serial fetal magnetic resonance imaging of cloacal exstrophy.

Cloacal exstrophy (CE) is a rare congenital malformation involving the urinary, intestinal, and genital systems. We present a case of CE in which characteristic findings were detected at two serial fetal magnetic resonance imaging (MRI) sessions. At 18 weeks' gestation, the initial fetal MRI revealed a cystic mass protruding from the infra-umbilical abdominal wall. During fetal development, the cystic mass disappeared, and an omphalocele and heterogeneous soft tissue mass were recognized at 28 weeks' gestation. The bladder was not visualized on either examination. CE can be diagnosed by prenatal MRI, thereby permitting prenatal counseling and appropriate postnatal management.