What are Renal Cysts

Cysts are enclosed sac like structures that contain liquid or semisolid substance. In general, cysts can be present in any part of the body. They are named according to their location in the body; for example cysts on the skin are called sebaceous cysts, whereas those present in the nerve roots and liver are referred to as tarlov cysts and liver cysts respectively. Likewise, renal cysts are the cysts present in the kidney. It is common to have more than one renal cysts, which in maximum cases, are benign (not dangerous). However, the severity of the symptoms may vary according to the underlying causes of the condition.

Renal Cysts: Classification

There are several types of renal cysts, classified based on the appearance of the fluid-filled lesions. The most common types are simple and complex renal cysts. The former type is small, appears round, spherical or oval in shape with smooth and thin wall. Usually, simple renal cysts are harmless and asymptomatic without any clinical implications. People who are above 50 years are at a higher risk of developing renal cysts. It is estimated that more than 50 percent of people over 50 years have renal cysts.

More than one simple cysts may be present in an individual. Simple renal cysts are called hyperdense, if there is presence of blood on the walls of the cysts. Bilateral renal cysts refer to the presence simple cysts in both the kidneys. In the complex type, the cysts are characterized by irregularities in the wall lining. Complex renal cysts may have septations (walls within the same cyst), calcifications (deposition of calcium) and enhancements (a part of the cysts receives blood supply).

Renal Cysts: Causes and Symptoms

Renal cysts can be present at birth (congenital) or acquired later due to obstruction in the kidney tubules. It may be caused due to underlying diseases and disorders. For example, renal cysts are more common among people with polycystic kidney disease, medullary cystic disease, medullary sponge kidney and chronic renal failure. Those who undergo frequent dialysis, especially hemodialysis are susceptible to develop renal cysts. Tapeworm infestation can also lead to the development of renal cysts.

In majority of the cases, renal cysts cause no symptoms. In fact, many people with renal cysts are not aware of their condition. Some of the symptoms that may be developed due to complicated renal cysts are kidney pain, difficulty in urination, frequent urination, presence of blood tinge in urine, hypertension, pain on the belly, side and back. In case of renal cysts caused by tapeworm infestation, the symptoms usually accompany the presence of tapeworm segments and/or eggs in urine and stool. At times, renal cysts may lead to complications like kidney infections and cancer.

Renal Cysts: Diagnosis and Treatment

Renal cysts are identified after conducting imaging tests such as ultrasound, CT (computed tomography) and magnetic resonance imaging (MRI) scan. There are no specific treatments for small and benign renal cysts. If there are any noticeable signs and symptoms of renal cysts, then the physician may conduct imaging tests in order to detect any changes in the cyst size. In case of a growing or cancerous renal cyst, surgical removal is necessary for the cure. Another effective treatment option for complicated renal cysts is the percutaneous sclerotherapy, conducted by injecting sterile alcohol, particularly ethanol.