A 48-year-old alcoholic man presents with severe epigastric pain radiating to the back. Serum lipase is markedly elevated. At laparotomy, the omentum and peripancreatic fat show scattered chalky white areas. Microscopy reveals shadowy outlines of necrotic adipocytes with basophilic calcium deposits at their margins. The chalky white foci are formed by which mechanism?

• A Deposition of immune complexes containing fibrin in fat lobules
• B Coagulative necrosis of adipocytes preserving ghost cell outlines only
• C Combination of released fatty acids with calcium to form calcium soaps ✓
• D Metastatic calcification secondary to hypercalcemia from bone destruction

Explanation

In enzymatic fat necrosis of acute pancreatitis, pancreatic lipase digests peripancreatic fat, liberating fatty acids that combine with calcium to form insoluble calcium soaps (saponification), visible grossly as chalky white deposits and microscopically as basophilic deposits at necrotic adipocyte margins. Option D is killed by the fact that serum calcium here is normal to low, and the calcification is dystrophic, occurring in injured tissue despite normal mineral homeostasis.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.