Splenic infarcts – gross Coagulative necrosis.
Two large infarctions (areas of coagulative necrosis) are seen in this sectioned spleen.Since the etiology of coagulative necrosis is usually vascular with loss of blood supply, the infarct occurs in a vascular distribution. Thus, infarcts are often wedge-shaped with a base on the organ capsule.
The small intestine is infarcted. The dark red to grey infarcted bowel contrasts with the pale pink normal bowel at the bottom
Microscopically, the renal cortex has undergone anoxic injury at the left so that the cells appear pale and ghost-like. There is a hemorrhagic zone in the middle where the cells are dying or have not quite died, and then normal renal parenchyma at the far right.This is an example of coagulative necrosis3 stages of coagulative necrosis (L to R) -- micro
Extensive acute inflammation may lead to abscess formation, as seen here with rounded abscesses (the purulent material has drained out after sectioning to leave a cavity) in upper lobe and lower lobe
The liver shows a small abscess here filled with many neutrophils. This abscess is an example of localized liquefactive necrosis
Grossly, the cerebral infarction at the upper left here demonstrates liquefactive necrosis.Eventually, the removal of the dead tissue leaves behind a cavity
This is liquefactive necrosis in the brain in a patient who suffered a "stroke" with focal loss of blood supply to a portion of cerebrum.
As this infarct in the brain is organizing and being resolved, the liquefactive necrosis leads to resolution with cystic spaces
At high magnification, liquefactive necrosis of the brain demonstrates many macrophages at the right which are cleaning up the necrotic cellular debris
Microscopically, caseous necrosis is characterized by acellular pink areas of necrosis, as seen here at the upper right, surrounded by a granulomatous inflammatory process
Microscopically, fat necrosis adjacent to pancreas is seen here. There are some remaining steatocytes at the left which are not necrotic. The necrotic fat cells at the right have vague cellular outlines, have lost their peripheral nuclei, and their cytoplasm has become a pink amorphous mass of necrotic material
Ch. 1, p. 2, Fig. 1-2 injury at the left so that the cells appear pale and ghost-like.Myocyte adaptation
See Ch. 1, p. 3. Fig. 1-3 injury at the left so that the cells appear pale and ghost-like.Physiologic hypertrophy
There are some muscle fibers here that show atrophy.The number of cells is the same as before the atrophy occurred, but the size of some fibers is reduced.This is a response to injury by "downsizing" to conserve the cell
See also Ch. 1, p. 5, Fig. 1-4 injury at the left so that the cells appear pale and ghost-like.Physiologic atrophy
The testis at the right has undergone atrophy and is much smaller than the normal testis at the left
See Ch. 1, p. 5, Fig. 1-5 injury at the left so that the cells appear pale and ghost-like.Squamous metaplasia
Prostaglandins synthesized at the site of inflammation
Compliment proteins chemotaxis, cytolysis and opsonization at the site of inflammation