Acute Tubular Necrosis (ATN)

Epidemiology & Etiology:

• Ischemia
• Shock
• Decreased effective circulating blood volume
• PAN
• Malignant hypertension
• Hemolytic-uremic syndrome
• Direct toxicity
• Drugs
• Radiocontrast dyes
• Myoglobin
• Hemoglobin
• Radiation
• Acute tubulointerstitial nephritis
• DIC
• Urinary obstruction

Common sites:

Gross features:

Histologic features:

• focal tubule cell injury (straight portion of proximal tubule and the ascending thick limb in the renal medulla are especially vulnerable):
• cellular swelling
• loss of brush border
• blebbing / vacuolization
• loss of polarity
• cell detachment and sloughing into lumen
• necrosis
• apoptosis
• casts (particularly distal tubules and collecting ducts):
• eosinophilic hyaline casts
• pigmented granular casts
• interstitial edema
• accumulations of leukocytes in dilated vasa recta
• epithelial regeneration:
• flattened epithelial cells with hyperchromatic nuclei
• mitotic figures

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

Other features:

• Most common cause of acute renal failure
• Ischemic and toxic types – look similar

References:

· Kumar V, Fausto N, Abbas A. Robbins & Cotran Pathologic Basis of Disease, Seventh Edition. 7th ed. Saunders; 2004:1552.