Almost all of these cysts are asymptomatic. In rare instances, hematuria, pain, hypertension, or infection can complicate a simple renal cyst. In some patients, a locus for this abnormality has been found on chromosome 4. They are lined by epithelium and contain fluid derived from the glomerular filtrate and modified by the action of the tubular epithelial lining. Cyst formation begins in utero, and cysts increase in size and number as the patient ages.
Most patients come to medical attention in middle age.
As the cysts enlarge, they compress adjacent normal tissue and lead to interstitial scarring. Symptoms and signs include flank or back pain, abdominal masses, gross hematuria, urinary tract infections, and stone disease. Patients are typically less anemic than expected for their degree of renal insufficiency. The kidneys typically enlarge progressively as the patient ages and the cysts grow. Control of infections and hypertension may slow the progression of renal dysfunction.