Kidney Cyst


A kidney cyst  or renal cyst, is a fluid collection within the kidney.

Most kidney cysts are “simple” or “benign” meaning no treatment is required. Some cysts are more “complex” and require either close radiographic imaging (with either a CT scan or MRI) or surgery since these cysts can be cancerous. They are quite common, and the incidence increases with advancing age.

Kidney cysts may be part of a genetic disease that results in a slow, progressive decrease in kidney function. In this scenario, there is usually a family history of kidney disease.

Symptoms of Kidney Cysts

Quite commonly, no symptoms are present in individuals with renal cysts. They are usually discovered during an imaging study (ultrasound, CT scan, or MRI) obtained for some other reason such as abdominal pain.

Conversely, some individuals with large or multiple renal cysts may experience blood in the urine (hematuria), flank pain, high blood pressure and fever (if the cyst becomes infected).

Evaluation and Treatment

If a kidney cyst is determined to be “simple”, no further evaluation is necessary.
If the cyst is deemed “complex”, it may require periodic imaging to assess its growth, at which time surgery to remove the cyst or the entire kidney may be advised due to the increased risk of kidney cancer. Some complex renal cysts require immediate removal due to their risk of harboring cancer.

In some individuals, renal cysts result in a slow, progressive decline in kidney function. These individuals may require removal of the kidney due to repeated infections or chronic pain.

When the kidney cyst is “complex” and removal of the cyst or the entire kidney is advised, this can usually be accomplished using a minimally-invasive approach such as laparoscopic or robot-assisted laparoscopic surgery. In cases of large kidney cysts, an open procedure to remove the kidney may be advised. Discuss all surgical options with your urologist to decide what’s best for you.