Multicystic dysplastic kidney: diagnostic considerations and management.

A protocolled diagnostic approach for assessing various cystic and solid masses occurring in the neonate and infant, with particular emphasis on renal masses, is described. This protocol uses diagnostic examinations in such a sequence as to establish the diagnosis with acceptable confidence by the least invasive procedure and, therefore, at minimal cost in time, money, and risk to the patient. Early definitive diagnosis permits triage of patients into a group benefiting from immediate surgical intervention versus those with entities that can safely be followed up expectantly. Moreover, certain diagnostic procedures such as antegrade pyelography can be expanded to serve therapeutic purposes as a temporizing percutaneous nephrostomy, thus preserving renal parenchyma and hopefully improving the general condition of the neonate until a definitive surgical procedure can be safely undertaken to correct the underlying deficit.