Is it advisable to remove a multicystic dysplastic kidney?

Q: My son is 4 years old. We discovered a cyst on his right kidney when he was in the womb. His urologist went in through his penis, as he describes and popped the cyst when he was 2 weeks old. This caused damaged to his kidney and now it is functioning at 1%. He has had no infections and no reflux. There is not much left to the kidney. The doctor is hoping that it would just completely disappear. However, this has nor happened and the doctor has advised to remove what is left of it. Is this necessary?

A:From what you describe, your baby has a multi cystic dysplastic kidney which is non-functional. These sometimes involute (spontaneously disappear) in the first year. If it hasn't, then it is best removed since there is a theoretical chance of tumour development in these kidneys later.