A 50-year-old chronic alcoholic presents to the emergency room with 12 hours of severe abdominal pain. The pain radiates to the back and is associated with an urge to vomit. Physical examination discloses exquisite abdominal tenderness. Laboratory studies show elevated serum amylase. Which of following morphologic changes would be expected in the peripancreatic tissue of this patient?

Fat necrosis. Saponification of fat derived from peripancreatic fat cells exposed to pancreatic enzymes is a typical feature of fat necrosis. Lipase, released from pancreatic acinar cells during an attack of acute pancreatitis, hydrolyzes fat into fatty acids and glycerol. Free fatty acids bind with calcium to form soaps, which is a process known as saponification. Hypocalcemia is a typical finding in patients who had a recent bout of acute pancreatitis. Fat necrosis in acute pancreatitis- areas of white chalky deposits represent foci of fat necrosis with calcium soap formation (saponification) at sites of lipid breakdown in the mesentery.