A 26-year-old woman with accelerated hypertension has fundal hemorrhages and papilledema. A renal biopsy shows necrosis of arteriolar walls with a smudgy, intensely eosinophilic appearance of the vessel wall. Special staining demonstrates fibrin within the necrotic wall. This pattern of vascular necrosis results primarily from:

• A Accumulation of oxidized LDL within the intima with cholesterol clefts
• B Caseous destruction of the media by granulomatous inflammation
• C Enzymatic digestion of the media by lysosomal enzymes of infiltrating neutrophils
• D Deposition of plasma proteins, including fibrin, in the vessel wall with loss of endothelial integrity ✓

Explanation

Fibrinoid necrosis is characteristically seen in malignant hypertension and immune-mediated vasculitis. Injury to the endothelium and smooth muscle allows leakage of plasma proteins, including fibrin, into the vessel wall, producing the smudgy, bright pink, amorphous appearance on H and E. Neutrophilic enzymatic digestion (option C) describes liquefactive necrosis of abscesses, not vessel walls. The name derives from the fibrin-like (fibrinoid) staining quality of the deposited material, even when fibrin itself is scant.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.