As we enter our fourth week of Pathology 1 class with Dr. Zungia, I’ve starting to realize that everything I have learned in MD1-MD3 is starting to click. Last week in Pathology we learned about cellular injury and cellular death. As a group we learned about the differences in reversible cell injury along with cellular adaption and the several causes of cellular death. Our last few lectures consisted of Dr. Zuniga explaining about different types of necrosis and where each occurs on the body. He told us about the coagulative necrosis, liquefactive necrosis, caseous necrosis, fat necrosi
s, fibrinoid necrosis and gangrenous necrosis.
Coagulative necrosis is commonly seen in patients who experience hypoxia due to ischemic injury such as in a myocardial infarction. Coagualtive necrosis is seen in the heart, kidneys, and liver due to the denaturing and coagulation of proteins with in the cytoplasm of the cells in these vital organs. Liquefactive necrosis is cellular destruction by hydrolytic enzymes; this is typically due to autolysis and heterolysis.
Liquefactive necrosis occurs in abscesses, brain infarcts, and pancreatic necrosis. Caseous necrosis is basically a combination of both coagulative and liquefactive necrosis. When someone has caseous necrosis you can see a soft, friable, “cottage cheese” like tissue. Caseous necrosis is associated with granulomas (localized area of macrophages) which secrete lytic enzymes that cause the caseous process of necrosis. Caseous necrosis is seen in Tuberculosis and granulomas disease.
Fat necrosis is typically seen with trauma. Fat necrosis is seen in the adipose tissues of the body which become necrotic by the action of lipases on adipocytes. Typically adipose tissue has a yellow color, but during the process of fat necrosis, the adipose tissue looks chalky white.
Fibrinoid necrosis occurs due to acute immunologic injury and vascular hypertensive damage. Fibrinoid necrosis is seen in rheumatic heart disease and rheumatoid arthritis. Gangrenous necrosis is common in lower limbs, gallbladder, GI tract, and testes.
Gangrenous necrosis is defined in 2 types: Dry and Wet gangrenous necrosis. Dry gangrene is typically associated with Coagualtive necrosis and wet gangrene is associated with liquefactive necrosis.