A3 week old child presents with an abdominal mass. What is the most common cause of the presentation?

Ans. is 'c' i.e., Multicystic dysplastic kidney Multicystic renal dysplasia (multicystic dysplastic kidney)* Multicystic dysplastic kidney is a congenital condition in which the entire kidney is dysplastic with a preponderance of cysts.* It can result from ureteral atresia. Kidney size is highly variable.* Kidney is replaced by multiple cysts of varying sizes that do not communicate and no identifiable parenchyma is present.* MCDK usually is unilateral and generally is not inherited. Bilateral MCDKs are incompatible with life.* Contralateral vesicouretral reflux is present in 15% cases. Contralateral hydronephrosis is present in 5 - 10% cases.* It is the most common cause of an abdominal mass, but the vast majority are nonpalpable at birth and it is the most common cystic disease in neonates.* In most cases, it is discovered incidentally during prenatal sonography.* In some patients, the cysts are identified prenatally, but the cysts regress in utero and no kidney is identified on imaging at birth.* Sonography shows the characteristic appearance of a kidney replaced by multiple cysts of varying sizes that do not communicate, and no identifiable parenchyma is present