The dilemma of prenatal diagnosis of bladder exstrophy: a case report and a review of the literature.

Bladder exstrophy is a very rare congenital anomaly characterized by the exteriorization of the viscera on the abdominal surface, low insertion of the umbilical cord, divergent pubic rami and abnormal exterior genitalia. We report a case of prenatal diagnosis of fetal bladder exstrophy in which the urachus resembled the normal bladder. Considering that non-visualization of the bladder is one of the main findings in cases of bladder exstrophy, special attention should be given to fetal lower abdominal cystic images in order to differentiate them from a normally positioned fetal bladder. A review of the literature together with a sonographic study of the urachus is provided.