American Urological Association - Renal Cortical Necrosis
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Renal Cortical Necrosis

Image A

Image B

  • Usually bilateral, diffuse or multifocal kidney involvement and results from an extrarenal process.
  • Most commonly encountered as an obstetrical complication (50-60%), such as abruptio placenta, placenta previa.
  • Other causes include gram- septicemia (30-40%) (E. coli, K. pneumonia), and rarely, toxicity, shock due to ketoacidosis, acute pancreatitis, burns, acute blood loss.
  • Normally renal blood flow is 80% cortex and 20% medulla; increase susceptibility to ischemic insults.
  • Outer rim of renal capsule spared because capsular vessels supply it.
  • Presents with prolonged decrease or absent urine output, flank pain, gross hematuria.
  • 20% of ARF in pregnancy is due to cortical necrosis; high fatality also from extrarenal cause.
  • ~1/2 eventually develop CRF.
  • Early phase shows yellow discoloration of cortex (hemorrhagic if blood supply is reestablished) and subcapsular and juxtamedullary congestion.
  • Late phase shows cortical fibrosis with thinning and calcifications.
  • Histology:
  • Widespread coagulative necrosis (preserve ghost cell outlines) of cortex (image B).
    • Subcapsular (1-2mm) and medulla spared from the process.
    • Tubules in non-necrotic area may have acute tubular injury and thrombi may be seen in vessels including glomeruli.