Ischemic necrosis of tubular cells in the kidney is called what?

• A. Acute tubular necrosis
• B. Acute interstitial nephritis
• C. Pyelonephritis
• D. Nephrotic syndrome

Answer: (A)

Ischemia causing necrosis of tubular epithelial cells in the kidney is acute tubular necrosis. The tubular epithelium, especially in the proximal tubule and thick ascending limb, is highly susceptible to hypoxic injury, so cells die and slough, which can obstruct tubules and impair filtration. This is distinct from acute interstitial nephritis, which is inflammation of the interstitium often drug- or infection-related; pyelonephritis, which is infection of the renal pelvis and parenchyma; and nephrotic syndrome, which is a glomerular disease with heavy proteinuria. Clinically ATN often presents with oliguria and rising BUN and creatinine, and urinalysis may show muddy brown granular casts reflecting tubular debris.