Kidney cysts are fluid filled pouches that form on the kidney. It is not well known as to why these form. Most of the time they are found incidentally during an ultrasound or Cat Scan (CT). There is some evidence that suggests males tend to have renal cysts more than females. Statistics show that 50% of the population older than age 50 will have at least one renal cyst, and individuals may have cysts grow slowly by size or number with age. Simple cysts are different than cysts that form on a patient with Polycystic Kidney Disease which is an inherited disease.
More than one cyst can form on the kidney. Simple cysts are benign and will not progress into cancer. They can grow over time and cause back pain if they become infected or press on other organs. Having said that, the vast majority of cysts are small, and rarely if ever will cause any issues. They also can rarely cause kidney failure, but this is often associated with Polycystic Kidney Disease.
In most cases, treatment or follow up is not required for kidney cysts. If they are causing significant back pain or could be a source of renal failure, an ultrasound guided needle aspiration can be performed. There is a possibility the cyst will return after an aspiration however, an alcohol based solution is injected to fill the cyst to try and prevent re-occurrence. In some cases, we can also do a surgical “cyst decortication”, where the lining of the cyst is removed. At the Austin Urology Institute, we perform this via robotic, laparoscopic technique if indicated.