fibrinoid necrosis
Summary
Fibrinoid necrosis is a type of tissue necrosis characterized by the deposition of fibrin-like material in blood vessel walls, typically occurring in acute hypertension, vasculitis, and immune complex diseases. It results from acute vascular injury with increased permeability, allowing plasma proteins to leak into vessel walls where they undergo denaturation.
Detail
Fibrinoid necrosis occurs when acute vascular injury leads to increased endothelial permeability, allowing plasma proteins (particularly fibrinogen, immunoglobulins, and complement) to leak into and accumulate within blood vessel walls. These proteins undergo denaturation and appear as homogeneous, eosinophilic (pink), fibrin-like material on histology. The process involves endothelial damage, loss of vascular integrity, and subsequent protein extravasation. Common causes include malignant hypertension (where it affects arterioles in kidney, brain, and retina), autoimmune vasculitis (such as polyarteritis nodosa, SLE), immune complex deposition diseases, and acute transplant rejection. In malignant hypertension, fibrinoid necrosis of renal arterioles leads to acute kidney injury and the characteristic 'flea-bitten kidney' appearance. The condition represents irreversible vascular damage and often indicates severe underlying pathology requiring immediate medical intervention.
Sources
- Robbins and Cotran Pathologic Basis of Disease
- Pathoma: Fundamentals of Pathology
- Kumar, Abbas, and Aster: Robbins Basic Pathology
- First Aid for the USMLE Step 1
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