PANCREATIC FAT NECROSIS 387 



Fat Necrosis" 



ThrouKh iisaj.'c (his Icrm Ikis come to indicate a specific form of 

 necrosis of fat tissue, which is characterized l)y a focal, circumscribed 

 arran<i,ement, and by the splitting of the fat in the necrotic area into 

 fatty acids and glycerol, the latter disappearing, the former com- 

 bining with bases to form soaps. ^^ In practically all cases fat necrosis 

 is produced by the action of pancreatic juice upon fat tissue,*^' pre- 

 sumably through the action of the enzymes it contains, and the con- 

 dition can be produced experimentally b}'- any procedure that causes 

 escape of the pancreatic juice from ito natural channels. 



Langerhans" made the first studies cf the nature of the changes 

 in fat necrosis and established the fact that the fat of the cells is 

 split into its components, and that the fatty acids combine (at least in 

 part) with calcium. Dettmer-^ found that, although fresh pancreatic 

 juice caused fat necrosis, a commercial preparation of trypsin did not 

 do so, and, therefore, he concluded that probably the lipase of the 

 pancreatic juice was the active agent. Flexner-"* supported this con- 

 tention by demonstrating the presence of a fat-splitting enzyme in 

 foci of fat necrosis, which was corroborated by Opie.^-^ The latter^® 

 was also able to demonstrate the presence of Kpase in the urine of a 

 patient with fat necrosis," and the highest values for amylase in the 

 blood and urine are found in pancreatitis (Stocks).-^ 



In a study of the pathogenesis of fat necrosis, particularly with 

 reference to the question whether the lipase or the trypsin of the 

 pancreatic juice was responsible, Wells-^ found that typical fat necro- 

 sis could be produced by injecting extracts of fresh pancreas into 



^^ General literature will be found in the articles cited in the text; also in 

 Opie's "Diseases of the Pancreas;" and in Truhart's "Pankreas-Patholoeie," 

 Wiesbaden, 1902. 



-" The fatty acids form masses of crystals in the fat-cells, and they can also 

 be demonstrated microchemically by Benda's method (Virchow's Arch., 1900 (161), 

 194), which consists of staining with a copper acetate mixture, blue-green copper 

 salts of the fatty acids being formed. 



21 Wulff (Berl. klin. Woch., 1902 (39), 734), claims to have observed an excep- 

 tion to this rule, but his account is not by itself convincing. Fabyan (Johns 

 Hopkins Hosp. Bull., 1907 (18), 349) reports a case of multiple subcutaneous 

 fat necrosis without pancreatic lesions, in a 14 days' old baby, and gives a re- 

 view of other similar cases. This case, however, may be one of scleroderma 

 C. S. Smith, Jour. Cut. Dis., 1918 (36), 436). 



" Virchow's Arch., 1890 (122), 252. 



^'Dissertation, (Jottingen, 1S95. 



24 Jour. Exper. Med., 1897 (2), 413. 



" Contrib. of pupils of W. H. Welch, Baltimore, 1900, p. 859; Johns Hopkins 

 Hosp. Rep., 1900 (9), 859. 



-^ Opie, "Diseases of the Pancreas," Lippincott, 1903, p. 156; Johns Hopkins 

 Hosp. Bull., 1902 (13), 117. 



2^ It yet remains to be seen if this is a constant occurrence, and also if the 

 lipase so excreted comes from the pancreas, for Zeri (11 Policlinico, 1905 (12), 733) 

 has found lipase in the urine in hemorrhagic nephritis and inflammation of the 

 urinary tract; also Pribram and Loewv, Zeit. physiol. Chem., 1912 (76), 489. 



28 (^lart. Jour. Med., 1916 (9), 216.' 



" Jour. Med. Research, 1903 (9), 70. 



