Renal Cyst
What is Renal Cyst
An encapsulated, fluid-filled growth that occurs in the kidney. Simple renal cysts are common and nearly always benign (noncancerous). Complex renal cysts, which may contain calculi (stones) and BLOOD, may be benign or cancerous. Most renal cysts, simple or complex, do not cause symptoms. Rather, the doctor detects them during diagnostic procedures, such as abdominal ULTRASOUND or COMPUTED TOMOGRAPHY (CT) SCAN, to evaluate other health concerns. When symptoms do occur, they may include a sensation of pressure if the cyst is large enough to pressure other structures in the abdomen or interfere with kidney function. Occasionally, a renal cyst grows large enough or in a location to cause significant PAIN.
Ultrasound or CT scan generally provides enough information for the nephrologist to determine whether a renal cyst appears suspicious. A needle biopsy, which removes a small sample of tissue and fluid from the cyst, can show whether the cyst is cancerous. The nephrologist may recommend a course of watchful waiting for benign cysts that cause no symptoms. Surgery is necessary to remove symptomatic or cancerous cysts. Recovery from such surgery—which may be laparoscopic or open, depending on the size and location of the cyst—is generally complete and without complications. The presence of multiple cysts may indicate POLYCYSTIC KIDNEY DISEASE, a genetic disorder in which numerous cysts form in the KIDNEYS as well as in other organs. Recurrent cysts require further evaluation.
See also NEPHROLITHIASIS; RENAL CANCER.
