[Is it necessary to remove polycystic kidneys?].

The Multicystic Dysplastic Kidney is the most frequent renal congenital anomaly and the second most common cause of an abdominal mass in the newborn. Traditionally, since this pathological entity was described as such by Spene in 1955, early resection has been deemed its best treatment. In the last decade, a conservative approach has been advocated by some authors, except for the patients presenting with concomitant abdominal pain or infection. In our hospital, relying on the support afforded by the echographic assessment of these patients, we have proposed an expectant behaviour in the management of this entity. So far, we have had the opportunity to follow the course of the disease in 15 patients with the diagnosis of Multicystic Dysplastic Kidney, with the result that in no one of them the size of the cystic mass increased, but instead the mass disappeared completely in one case, diminished greatly in three cases, had a moderate decrease in size in eight cases and in just three patients it has not varied in size. No patient has complained of abdominal pain or has become infected. In the face of such findings, we believe that early resection of the multicystic kidney is not warranted if no complications develop.