Fat necrosis is a term that is well fixed in medical parlance but does not in reality denote a specific pattern of necrosis. Rather, it is descriptive of focal areas of fat destruction, typically occurring as a result of release of activated pancreatic lipases into the substance of the pancreas and the peritoneal cavity.
This occurs in the calamitous abdominal emergency known as acute pancreatitis. In this disorder, activated pancreatic enzymes escape from acinar cells and ducts, the activated enzymes liquefy fat cell membranes, and the activated lipases split the triglyceride esters contained within fat cells.
The released fatty acids combine with calcium to produce grossly visible chalky white areas (fat saponification), which enable the surgeon and the pathologist to identify the lesions).
On histologic examination, the necrosis takes the form of foci of shadowy outlines of necrotic fat cells, with basophilic calcium deposits, surrounded by an inflammatory reaction.
See also
Necrosis
References
Robbins