Prenatal diagnosis of crossed ectopic multicystic kidney

The combination of multicystic kidney and crossed ectopia is very rare. In most of the affected children, diagnosis has been made postnatally by ultrasonographic examination to evaluate a palpated abdominal mass. We describe the third male newborn reported in the literature with a prenatally diagnosed crossed ectopic multicystic dysplastic kidney. As with isolated multicystic kidney, crossed ectopic multicystic kidney should be followed closely after birth by repeated ultrasound for spontaneous regression. Only in cases of anomalies of the contralateral (uncrossed) kidney should the question of surgical intervention be raised.