518 



THE CHEMISTRY OF TUMORS 



(d) Lipomas^^ have been studied by Schulz^*' and by Jaeckle.^^ 

 The former found in a retroperitoneal hpoma 75.75 per cent, of fat, 

 2.25 per cent, of connective tissue, and 22 per cent, of water. Of the 

 fat, 7.31 per cent, was in the form of the free fatty acids and 92.7 per 

 cent, as neutral fats. The fatty acids of the fat consisted of 65.57 

 per cent, oleic acid; 29.84 per cent, stearic acid; 4.59 per cent, pal- 

 mitic acid. Cholesterol was only qualitatively demonstrable. In the 

 connective tissue was found chondroitin-sulphuric acid. Lubarsch 

 found glycogen in lipomas only when they were degenerated. Jaeckle 

 observed the formation of calcium soaps in a calcifying lipoma, the 

 calcium being distributed as follows: calcium soaps, 29.5 per cent.; 

 calcium carbonate, 28.61 per cent.; calcium phosphate, 41.89 per cent. 

 The fats of lipomas he found practically identical with those of the 

 subcutaneous tissues, except sometimes for a deficiency in lecitliin, 

 as shown by the following figures: 



Composition op Fats in — 



Lipomas are able to hydrolyze fats and esters, their lipase behaving 

 in all respects like the lipase of normal areolar tissue.**** Lipoma fat 

 is hydrolyzed by lipase as readily as is normal human fat. No rea- 

 son for the reputed unavailability of lipoma fat for the metabolism 

 of the host could be found. It is doubtful if the fat of benign lipomas 



*^ In xanthoma tuberosum multiplex, which shows local deposits composed largely 

 of cholesterol esters and contains also pigment with the properties of a lipochrome, 

 the presence of hyper-cholesterolemia is disputed. (Roscnbloom, Arch. Int. Med., 

 1913 (12) 395; Schmidt, Dermatol. Zeit., 1914 (21), i:37). 



Edsall found the composition of the fat in the fatty tumors of adiposis dolorosa 

 (Dercum's disease) but little different from that of normal fat. (Cjuotod by 

 Dercum and McCarthy, Amer. Jour. Med. Sci., 1902 (124), 994). Martelli 

 (Tumori, 1918 (6), 1) on histological grounds states that in 2-3 per cent, of the 

 cells the fats are mi.xed with fatty acids, while cholesterol, phospholijiins and 

 chromolijjins are very scanty; he attributes the condition to disturbed lipogenesis 

 from enducrin-sympathetic disfunction. 



8" Pfluger's Arch., 1893 (55), 231. 



8^ Zeit. physiol. Chem., 1902 (36), 53. 



88 Wells, Arch. Int. Med., 1912 (10), 297; full review. 



