Physicians should be aware of the manifestations of medullary sponge kidney and nephrocalcinosis in patients with Beckwith–Wiedemann syndrome. In addition to nephrocalcinosis, renal cysts, recurrent pain associated with infundibular stenoses, nephroblastomatosis, and Wilms tumor have also been reported.[3] As shown in our case presentation, patients with medullary sponge kidney usually form cal...