Renal Cysts

RENAL CYSTS

Renal cysts are abnormal, fluid-filled sacs that arise from the kid-ney tissue. They may be genetic in origin, acquired, or associated with a host of unrelated conditions. Cysts of the kidney may be single or multiple (polycystic), involving one or both kidneys. Polycystic disease of the adult is inherited as an autosomal dom-inant trait and affects men and women equally.

Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease is a common in-herited condition, occurring in between 1 in 200 and 1 in 1,000 of the population. After diagnosis, patients are usually treated by nephrologists because of the risk of progression to ESRD. Almost two thirds (64%) of people with adult polycystic kidney disease also develop hematuria. Most episodes are due to UTIs and rup-ture of renal cysts that relate to the underlying anatomic abnor-malities. The symptoms are usually short-lived and resolve with conservative measures such as rest and antibiotic treatment. Renal stone disease is also common, occurring in 20% of patients. Frank hematuria is also a presenting symptom of common, but unrelated, disorders that may occur coincidentally. These patients must be evaluated to rule out a genitourinary cancer because hematuria is also a presenting symptom of urinary tract cancer. Simple noninvasive diagnostic studies such as transabdominal ultrasound and urine cytology may demonstrate additional pa-thology that needs treatment to reduce further morbidity (Dedi, Bhandari, Turney et al., 2001).

Polycystic renal disease is also associated with cystic diseases of other organs (liver, pancreas, spleen) and aneurysms of the cere-bral arteries. It has long been recognized that patients on long-term dialysis (both hemodialysis and peritoneal dialysis) develop multiple cysts on their nonfunctioning kidneys. Many of these cysts contain cancer cells.

Acquired Cystic Kidney Disease

An acquired form of polycystic disease occurring as a result of ESRD associated with dialysis is called acquired cystic kidney dis-ease. While most of the cysts remain benign, serious complications can develop. Acquired cystic kidney disease has been associated with cyst infection, cyst hemorrhage, retroperitoneal hemorrhage, and spontaneous rupture of the kidney; therefore, it is important for the nurse to be aware of this variation of cystic kidney disease (Dedi, Bhandari, Turney et al., 2001; Headley & Wall, 1999).

Clinical Manifestations

The kidney gradually enlarges, with signs and symptoms becom-ing apparent in the fourth or fifth decade of life. The patient reports abdominal or lumbar pain. Hematuria, hypertension, pal-pable renal masses, and recurrent UTIs are additional manifesta-tions. Renal insufficiency and failure usually develop in the end stages. Diagnosis of renal cysts is confirmed either by intravenous urography or CT scan.

Management

Because there is no specific treatment for polycystic renal disease, patient care focuses on relief of pain, symptoms, and complica-tions. Hypertension and UTIs are treated aggressively. Dialysis is initiated when signs and symptoms of renal in-sufficiency and failure occur. Genetic counseling is part of man-agement with polycystic kidney disease that is genetic in origin. The patient is advised to avoid sports and occupations that pre-sent a risk for trauma to the kidney. Simple cysts of the kidney usually occur unilaterally and differ clinically and pathophysio-logically from polycystic kidney disease. In such cases, the cyst may be drained percutaneously.