Cloacal dysgenesis diagnosis by prenatal ultrasound and MRI.

Cloacal malformations are a spectrum of congenital pelvic malformations that result from abnormal cloacal division during early embryogenesis. Depending on the timing of the developmental arrest, a spectrum of abnormalities can result, ranging from urogenital sinus malformations to cloacal dysgenesis. This case highlights the unique imaging features of cloacal dysgenesis, which is an extremely rare variant of this malformation spectrum. This variant is also the most severe manifestation of the cloacal malformation spectrum.