A 45-year-old alcoholic man presents with severe epigastric pain radiating to the back. Serum lipase is markedly elevated. Autopsy reveals chalky white flecks in peripancreatic adipose tissue and omentum. Microscopy of these areas shows shadowy outlines of necrotic fat cells admixed with basophilic calcium deposits and neutrophils. The pathogenesis of this lesion involves:

• A Deposition of immune complexes and plasma proteins in fat cell walls
• B Reactive proliferation of mesothelial cells producing keratinizing squames
• C Ischemic death of adipocytes with preservation of ghost outlines by denatured proteins
• D Enzymatic digestion of triglycerides by released lipases with conversion of fatty acids to calcium soaps ✓

Explanation

Fat necrosis in acute pancreatitis results from liberation of pancreatic lipases into inflamed adipose tissue. The enzymes digest triglyceride esters, and the released fatty acids then combine with calcium to form chalky calcium soaps, a process called saponification, which explains the basophilic deposits and gross white flecks. Ischemic fat death without enzymatic digestion occurs in trauma-related fat necrosis such as breast fat necrosis, which lacks calcium soap formation.

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.