A cyst is a fluid filled sac located in any organ of the body. Cysts in kidney are also called renal cysts. As there are two kidneys, the cysts can be unilateral (one sided) or bilateral (both the sides). Further cyst can be divided into two categories, simple cyst and complex cyst. Simple cyst is small in size, having oval or round shape.
Complex renal cyst has irregular shape. They can become cancerous. Symptoms of complex renal cyst are hematuria, dull and throbbing pain in the abdomen. Cause of complex renal cyst is congenital renal tubular defect and repeated dialysis, certain kidney diseases etc.
Complex Renal Cysts
The wall of simple cyst is thin and smooth. The fluid inside the simple cyst is clear and yellow. In most cases simple cyst are harmless without any symptoms. Many individuals over 50 years may have asymptomatic simple renal cyst. Simple renal cyst does not turn cancerous.
Complex renal cyst is different from simple renal cyst:
- It is irregular in shape.
- The inside of complex renal cyst is divided into many compartments with thin or thick walls.
- The cysts may contain calcium in its fluid.Due to this the cyst can get calcified.
- The thin wall of complex renal cyst may have blood supply.
- Complex renal cyst can become cancerous in some cases.
- Due to high risk of cancer, complex cyst has to be evaluated and observed frequently by your urologist.
- Your urologist may refer the Bosniak classification to diagnose whether the complex renal cyst is cancerous or has a potential to turn cancerous.
Symptoms Of Complex Renal Cyst
Most of the time complex renal cysts are asymptomatic; they are accidently detected while doing sonography for some other disease. However few of them can present with symptoms due to rise in the size and infection, leading to internal pressure on the kidney.
- Hematuria: blood in urine. Due to over distension, one of the cyst can rupture into the renal pelvis and causes bleeding.
- Dull and throbbing pain in the abdomen, either due to increased weight of the kidney, or due to tension within the cysts. Sometimes the pain mimics as that or a renal stone.
- Vomiting, fever and nausea may be felt in some individuals where the cyst gets infected.
- Enlarged size of kidney: the large knobby kidney can be discovered in the course of a routine examination by a physician.
- Urine protein: Most of the time there will be no excess of protein loss from the urine, which can cause nephritic syndrome.
- Decreased kidney function.
Causes Of Complex Kidney Cysts
- The cyst can be since birth or congenital due to obstruction of the kidney tubules.
- They can be acquired after birth.
- Parasitic infestation as that of a tape worm may be responsible for a renal cyst.
- Persons undergoing dialysis repeatedly are at a greater risk for getting complex renal cyst. It can be peritoneal dialysis or hemo dialysis.
- Complex renal cyst is present in polycystic renal disease, medullary cystic disorder and medullary sponge kidney disease.
- Complex renal cysts are also present in chronic renal failure.
- People above the age of 50 years.
- Complications include renal cancer, anemia, and progressive damage to the kidney leading to its failure.