ABSTRACT
Complete absence of one kidney occurs in 1 in 3000 live births The other formed kidney is usually hypertrophic. Ectopic kidney occurs when the mature kidney fails to reach its normal location in the lumbar region. Horseshoe kidney is the most common renal fusion anomaly, occurring in about1 in 400 live births with a male predominance. Multicystic dysplastic kidney is the second most common cause of an abdominal mass in newborns after hydronephrosis due to pelviureteric junction obstruction. Duplication of the ureter and renal pelvis is a common anomaly, with an incidence of approximately 1 in 150 births. Unilateral duplication is six times more common than bilateral. An ectopic ureter is one that drains to regions other than the bladder. Ureterocele is a cystic enlargement of the intramural ureter which probably occurs as a result of atresia of the ureteric orifice. Renal cysts can be broadly classified into sporadic, acquired and genetic causes.
