The last type of necrosis is fibrinoid necrosis

The last type of necrosis is fibrinoid necrosis.

Fibrinoid meaning fibrin like. Fibrinoid necrosis usually occurs in blood vessels. In some immune diorders the antigen antibody complexes get deposited in the blood vesssels. These complexes elicit an immune reaction leading to cell injury. This leads to fibrin leaking out of the blood vessel and giving a pinkish appearance around the blood vessels.

If you see in this image there is fibrinoid necrosis in an artery in a patient with polyarteritis nodosa. The wall of the artery shows circumferential bright pink area of necrosis with protein deposition and inflammation.