IPLab:Lab 1:Fat Necrosis
This was a 37-year-old female with chronic renal failureRenal failure is the severe reduction of renal function and often leads to reduced urinary output. that necessitated a renal transplant. Following transplantation, the patient developed a herpes simplex virus (HSV) infection in her nasal cavity, oral candidiasisCandidiasis is an infection by the fungus Candida in the oral cavity., pneumoniaIn alcoholics, aspiration pneumonia is common--bacteria enter the lung via aspiration of gastric contents., hematuriaHematuria is the presence of blood in the urine., pyuriaPyuria is the presence of white blood cells (pus) in the urine., and gastrointestinal bleeding. Subsequently, the patient became septicSepsis is the presence and persistence of pathogenic microorganisms and their toxins in the blood. and died.
Major findings at autopsy included extensive hemorrhagic bronchopneumonia (Pseudomonas aeruginosa) and multiple ulcers affecting the stomach and esophagus. There was also evidence of disseminated intravascular coagulationDIC is the development of small thrombi within the microcirculation throughout the body. (DIC) with multiple hemorrhages present. Firm, whitish foci of necrotic tissue were found in the fat around the pancreas.
A higher-power photomicrograph of the previous slide contains a small area of fat necrosis (1) in the upper right portion of the image. The fat necrosis is within the fat tissue that is normally found adjacent to the pancreas. The appearance of the pancreatic tissue in this area is somewhat disrupted due to autolysis (the pancreas autolyzes very rapidly after death) but there is some premortem necrosis as well.
This high-power photomicrograph demonstrates fat necrosis in the interlobular spaces of the pancreas. Note the granular blue-staining calcium deposits (arrows) within the fat cells. The clear areas represent artifact caused by the "washing-out" of fat from cells during tissue processing for histology.
Pancreatic Fat Necrosis
Focal areas of destruction of fat tissue resulting from abnormal release of activated lipases.
- What causes the formation of the white, chalky, nodules that are seen in the fat tissue adjacent to the pancreatic tissue?
Injury to the pancreas (infection, toxins, viruses, trauma, ischemia) causes release of activated pancreatic enzymes which liquefy fat cell membranes. The released lipases split the triglyceride esters contained within the fat cells and these released fatty acids combine with calcium to form the grossly visible chalky white nodules characteristic of fat necrosis.
- Bhatnagar A, Wig J, Vaiphei K, Majumdar S. Intracellular cytokines in cells of necrotic tissue from patients with acute pancreatitis. Eur J Surg 2001 Jul;167(7):510-7.
- LeWinter MM. Acute Pericarditis. NEJM 2014 Dec 18;371:2410-2416.