Fat necrosis is a form of necrosis

Necrosis

Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...

 characterized by the action upon fat

Fat

Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...

 by digestive enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s.

In fat necrosis the enzyme lipase

Lipase

A lipase is an enzyme that catalyzes the formation or cleavage of fats . Lipases are a subclass of the esterases.Lipases perform essential roles in the digestion, transport and processing of dietary lipids in most, if not all, living organisms...

 releases fatty acids from triglycerides. The fatty acids then complex with calcium

Calcium

Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

 to form soaps. These soaps appear as white chalky deposits.

It is usually associated with trauma

Physical trauma

Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...

 of the pancreas

Pancreas

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...

 or acute pancreatitis

Acute pancreatitis

Acute pancreatitis or acute pancreatic necrosis is a sudden inflammation of the pancreas. It can have severe complications and high mortality despite treatment...

.

It can also occur in the breast, the salivary glands http://peir.path.uab.edu/iplab/messages/598/425.html and neonates after a traumatic delivery.

See also

• Necrosis
  Necrosis
  Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
  
  
• Coagulative necrosis
  Coagulative necrosis
  Coagulative necrosis is a type of accidental cell death typically caused by ischemia or infarction.It is characterised by the 'ghostly' appearance of cells under light microscopy in the affected area of tissue. In coagulative necrosis the architecture of dead tissue is preserved for at least a...
  
  
• Liquefactive necrosis
  Liquefactive necrosis
  Liquefactive necrosis is a type of necrosis which results in a transformation of the tissue into a liquid viscous mass. Often it is associated with focal bacterial or fungal infections...
  
  
• Caseous necrosis
  Caseous necrosis
  Caseous necrosis is a form of cell death in which the tissue maintains a cheese-like appearance. The dead tissue appears as a soft and white proteinaceous dead cell mass.-Causes:...