Kidney Cysts

More common in people over age 50 and males, kidney cysts are fluid-filled pouches that sometimes form in or on kidneys.

Kidney cysts are often an incidental finding that have no associated symptoms and are usually non-cancerous.

Simple cysts are the most common type of cyst likely to affect kidneys.
These are not the same type of cysts related to polycystic kidney disease, an inherited disorder that often contributes to kidney failure.

Causes, Signs, and Symptoms

It’s not fully understood why kidney cysts form.

Smaller cysts usually do not produce any noticeable symptoms.

On rare occasions, kidney function may be affected if urine obstruction occurs.

One possibility is that the surface layer of a kidney may become weak over time and form a pouch that separates and becomes a cyst. Larger kidney cysts may cause upper abdominal pain or dull aches in the back area or on the sides of the body.

Examination and Diagnosis

An initial exam typically involves reviewing symptoms and medical history.

Kidney cysts are usually diagnosed on an ultrasound, a CT scan, or a magnetic resonance imaging (MRI) scan.

An ultrasound is commonly used to confirm the presence of a kidney cyst.

CT scanning allows physicians to assess the size and appearance of a cyst.

Kidney cysts may also be identified on a magnetic resonance imaging (MRI) scan.

Treatment Options

Image tests may be done on a regular basis to determine if the cyst is getting larger.

If persistent and potentially problematic symptoms are being experienced, the cyst may be punctured or drained.

During this process, a long needle is inserted into the cyst.

An alcohol solution may be inserted into the cyst after it’s drained to prevent it from reforming.

If simple kidney cysts are not associated with any symptoms then periodic observation is often recommended. Image tests can also help determine whether it is a simple cyst or has more worrisome features suggestive of a tumor.

Surgery for Kidney Cysts

Simple kidney cysts usually do not produce symptoms.

Some cysts slowly and progressively become larger over time.

Procedures performed today are often minimally invasive.

Cyst walls are surgically removed or burned to reduce regrowth.

While simple kidney cysts usually do not produce symptoms, some of these fluid-filled pouches slowly and progressively become larger over time, sometimes to the point where treatment is needed. This means smaller incisions are made and special instruments are used to access the cyst and drain it.

Next Steps

Kidney cysts are often an incidental finding that have no associated symptoms and are usually non-cancerous. Evaluation, imaging studies, and symptom review help determine whether observation or treatment is appropriate. If you have been diagnosed with a kidney cyst or are experiencing related symptoms, an evaluation can help determine the most appropriate course of care.