Renal medullary necrosis

Alternative names
Necrosis - renal papillae; Renal papillary necrosis

Definition
Renal papillary necrosis is a disorder of the kidneys 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 may result in impairment of the kidneys ability to concentrate the urine with ensuing polyuria (increased urine volume, usually in excess of 3 liters per day) and nocturia (frequent urination at night).

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. 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 is most commonly associated with analgesic nephropathy, diabetic nephropathy, renal transplant rejection, urinary tract obstruction, kidney infections and sickle cell anemia. Sickle cell anemia is a common cause of renal papillary necrosis in children.

Symptoms

     
  • Tissue in the urine  
  • Cloudy urine  
  • Dark, rust-colored, or brown urine  
  • Bloody urine  
  • Back pain or flank pain       o May be on only one side       o May be acute       o May be colicky or spasm-like pain

Additional symptoms that may be associated with this disease:

     
  • Painful urination  
  • Urinary hesitancy  
  • Increased Urinary frequency or urgency  
  • Polyuria (large urine volumes)  
  • Nocturia (urinating frequently at night)  
  • Incontinence  
  • Chills

Signs and tests
An examination may reveal tenderness on palpation over the affected kidney. There may be a history of chronic or recurrent Urinary tract infections. There may be signs of obstructive uropathy or renal failure.

     
  • A urinalysis may show sediment, casts, tissue, or Blood in the urine. Examination of tissue in the urine may show a necroticrenal papilla.  
  • An IVP may show obstruction or tissue in the renal pelvis or ureter.

Treatment
There is no specific treatment for renal papillary necrosis. If analgesic nephropathy is suspected as the cause, stop the use of suspected medications. This may allow spontaneous healing over time. If nephropathy is a result of diabetes or Sickle cell anemia, control of these disorders is important to reduce renal papillary necrosis. Renal failure should be treated as appropriate. The treatment of chronic or recurrent Urinary tract infections may include antibiotics.

Expectations (prognosis)
The probable outcome varies. If the underlying disorder can be controlled, a spontaneous remission is possible. The progression to renal failure is also possible.

Complications

     
  • Chronic or recurrent UTI  
  • Acute renal failure  
  • Chronic renal failure  
  • Acute unilateral obstructive uropathy  
  • Chronic unilateral obstructive uropathy  
  • Acute bilateral obstructive uropathy  
  • Chronic bilateral obstructive uropathy  
  • Metabolic acidosis  
  • Hyperkalemia  
  • Hypovolemia

Calling your health care provider
Call for an appointment with your health care provider any time there is bloody urine. Also call if other symptoms of renal papillary necrosis develop, especially after taking over-the-counter analgesics (pain medications).

Prevention
Control of Diabetes or Sickle cell anemia may reduce risk. Prevention of renal papillary necrosis from analgesic nephropathy includes careful moderation in the use of medications, including over-the-counter analgesics.

Johns Hopkins patient information

Last revised: December 8, 2012
by Armen E. Martirosyan, M.D.

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