Kidney cysts are spherical fluid filled cavities located in the tissues of the kidney. They may be single or multiple. Cysts are extremely common, occurring in over half of all people over age 50 and increasing with age, according to an article published in 2000 in the journal, "Nephrology Dialysis Transplantation." Most produce no symptoms or problems, and the cause is often unknown. However, there are some diseases associated with their development.
Inherited Disorders
Certain inherited disorders can cause kidney cysts. Polycystic kidney disease is an inherited disorder that causes many cysts to form in the kidney. It can lead to high blood pressure or kidney failure. Medullary cystic kidney disease often appears during the second decade of life and progresses slowly towards kidney failure.
Cancers
Cancers can also be in the form of cysts in the kidney. Renal cell carcinoma is the most common type of kidney cancer and can form a cyst in the kidney. Certain characteristics of these cysts on imaging, such as CT scan, differentiate cancerous cysts from benign ones. A benign cyst tends to be a fluid filled cavity with a thin wall. Cancerous cysts, such as renal cell carcinoma, tend to have thicker walls and divisions called septations.
Renal Failure and Hemodialysis
Chronic, or ongoing, kidney failure is associated with the development of kidney cysts. The association is even stronger for people who are undergoing hemodialysis, which is a filtering of the blood by a machine that is taking the place of normal kidneys. According to a September 1996 article in the medical journal, "Radiologic Clinics in North America," the cysts are usually multiple and small, at about half a centimeter in diameter, but can range up to 3 cm.
References
- "Nephrology Dialysis Transplantation"; The simple renal cyst; Anna-Maria Nahm, Eberhard Ritz; 2000
- Mayo Clinic: Polycystic Kidney Disease
- National Institutes of Health: Medline: Medullary Cystic Kidney Disease
- "Harrison's Priniciples of Internal Medicine"; Anthony S. Fauci; 17th Ed 2008
- "Radiologic Clinics in North America"; Acquired cystic kidney disease.; Levine; September 1996
