<prompt> Fibrinoid necrosis may be observed in all of the following exceptMalignant HypeensionPolyaeritis nodosaAschoff bodiesAll the above  <response>: Fibrinoid necrosis is a special form of necrosis, visible by light microscopy, usually in immune reactions in which complexes of antigens and antibodies are deposited in the walls of aeries. The deposited immune complexes, together with fibrin that has leaked out of vessels, produce a bright pink and amorphous appearance on HE preparations called fibrinoid fibrin-like by pathologists Fibrinoid necrosis is limited to small blood vessels. Typically, it involves small aeries, aerioles, and glomeruli affected by autoimmune diseases e.g., systemic lupus erythematosus or malignant hypeension and Polyaeritis nodosa Robbins Basic Pathology, 9th edition, page 10 