Q: My son was diagnosed with multicystic dysplastic kidney when he was 5 months inside me. His damaged left kidney was removed when he was 4 months old and on surgery they discovered that his right kidney was horseshoe shaped with a small cyst, which seems only on the outer layer of his existing kidney. The tests to determine the functioning of the existing kidney were all good. I am worried about the cyst. I am taking him for a checkup with ultrasound every year. He is four years old now. Please advise.

A:A single kidney is good enough for a person to live a normal life span. A cyst in the kidney is usually benign. I recommend a yearly ultrasound of the kidney to see for any changes in the cyst.