Renal papillary necrosis

Alternative names:

necrosis of the renal papillae; renal medullary necrosis

Definition:

A disorder of the kidney involving death of some or all of the renal papillae.

Causes, incidence, and risk factors:

The renal papillae are the areas of the kidney where the openings from the collecting ducts enter the renal pelvis. Necrosis (tissue death) of this area allows urine to leave the renal tubules before passing through the parts of the tubules that are responsible for concentrating, diluting, and acidifying the urine.

The necrotic tissue may be sloughed off, and it may be present in the urine as tissue, or the tissue may obstruct the renal pelvis or the ureter causing obstructive nephropathy. Presence of necrotic tissue in the urine increases the risk of urinary tract infections. Necrosis of multiple papillae in the kidney can lead to eventual failure of that kidney.

Renal papillary necrosis occurs in about 2 out of 10,000 people. It is most commonly associated with analgesic nephropathy. It also occurs in diabetic nephropathy, and the risk is increased when there is a history of sickle cell anemia. Sickle cell anemia is a common cause of renal papillary necrosis in children.