a local reaction to injury, occasionally observed in the walls of blood vessels and in parenchymal cells of various organs in reacting to certain chemicals, viruses, and other intracellular agents; the response is characterized by degenerative changes in the cytoplasm and nucleus, frequently resulting in necrosis, but exudation (if any) is ordinarily observed only in the wall of the affected vessel, or in the interstices immediately adjacent to the affected vessel or parenchymal cells. Syn: degenerative inflammation.