50% moality rates in 6-12 months, hence the designation "malignant." - These patients had vascular lesions called "fibrinoid necrosis" with the breakdown of the vessel wall, deposition of eosinophilic material including fibrin, and a perivascular cellular infiltrate. Fibrinoid necrosis- obliteration of glomeruli and loss of tubular structures- Progressive kidney failure - without dialysis leads to early moality in untreated malignant-phase hypeension- Endothelial injury can induce microangiopathic hemolysis- A separate lesion may occur in the larger interlobular aeries in some patients with the hyperplastic proliferation of the vascular wall cellular elements, deposition of collagen, and separation of layers designated the "onion skin" lesion.- Treatment: Antihypeensive therapy is the mainstay of therapyRef: Harrison's 18/e p2047">