Fibrinoid Necrosis of Blood Vessels

Compartment: Vessels

Illustration of a small dermal blood vessel with its wall replaced by smudgy, eosinophilic fibrinoid material, surrounded by fragmented neutrophil nuclei and extravasated red blood cells.
Fibrinoid necrosis: eosinophilic degeneration of the vessel wall with leukocytoclasia, the hallmark of vasculitis.

Definition: Vessel wall destruction where the damaged wall is replaced by amorphous, brightly eosinophilic material (fibrin, immunoglobulin, complement) — the hallmark of leukocytoclastic vasculitis.

Clinical Context: Leukocytoclastic vasculitis, Granulomatosis with polyangiitis, Erythema elevatum diutinum

Key Feature: Smudgy, deeply eosinophilic vessel wall with neutrophilic nuclear debris (leukocytoclasia) and red cell extravasation.

🔗 Related Terms: Arborizing Vessels

See this in a real case: Drug-Induced IgA Vasculitis (Leukocytoclastic Vasculitis) →