LIPINS OF TUMORS 503 



not acquire the enzyme, xanthine-oxidase, which is a characteristic 

 enzyme of this organ. Tlie hver tissue between the cancer nodules 

 seems to oxidize purines less actively then normal liver tissue. Long-*' 

 has also found similar conditions in tumors from sheep, pigs and cattle, 

 observing that primary carcinoma of the liver does not contain xan- 

 thine oxidase, a point of interest in view of the fact that in the develop- 

 ment of mammals the xanthine oxidase does not appear until late. 

 Water extracts from various tumors have been found to contain small 

 amounts of free purines, chiefly adenine, guanine and hypoxanthine 

 (Drummond).''- 



Lipins. — Tumor cells seem to contain much the same fats and lip- 

 oids as normal cells, and, as far as known, in much the same proportions 

 as characterize the cells from which the tumors arose. Thus Wells^* 

 found that hypernephromas show the same high proportions of lecithin 

 and cholesterol as he found in normal adrenal, and as are found in 

 the renal cortex. Other malignant tumors have much less lipoids and 

 fats( see Hypernephromas). A secondary carcinoma of liver cells, 

 metastatic in the skull, was found by Prym^" to show the same sort 

 of fatty infiltration that is characteristic of fatty liver cells. On ac- 

 count of the poor blood supply of many tumors, fatty changes are 

 usual, occurring under the same conditions and showing the same 

 microscopic features as fatty degeneration in other tissues,''*' being 

 more common in malignant than in benign tumors; especially abund- 

 ant in squamous cell carcinomas, and scanty in sarcomas. Crystals 

 of cholesterol or cholesterol compounds are described in tumors by 

 White. '*^ Dewey** found the chief lipoid in jaw tumors to be choles- 

 terol, with more or less free fatty acids and soaps, according to mi- 

 crochemical determinations. Even lipoma fat shows no difference 

 from normal fat,"*^ and the depot fat of tumor patients is quite the same 

 as in patients with other diseases associated with equal wasting, *° 

 in whom some increase in unsaponifiable material (cholesterol) is usual. 

 Murray^^ says that the lipoids of degenerating uterine fibroids are 

 strongly hemolytic, which may account for the so-called ''red degen- 

 eration" of these tumors. Freund and Kaminer^- suggest that the 

 fatty acids of tissues are of importance in determining whether a tissue 

 is a suitable soil for secondary growth, these substances being deficient 

 in tissues where growths develop. Mitochondria, which seem to be 

 closely related to the intracellular lipins, show no constant differences 



" Jour. Exper. Med., 1913 (18), 512. 

 *"■ Jour. Med. Res., 1908 (17), 461. 

 « Frankf. Zeit. Path., 1912 (10), 170. 



« See Haga, Berl. klin. Woch., 1912 (49), 342; Joannovics, Wien. klin. Woch. 

 1912 (25), 37. 



*" Jour. Path, and Bact., 1908 (13), 3. 



*8 Jour. Cancer Res., 1919 (4), 263. 



" See Wells, Arch. Int. Med., 1912 (10), 297. 



*» Wacker, Zeit. physiol. Chem., 1912 (78), 349; 1912 (80), 383. 



°i Jour. Obst. Gyn. Brit. Emp., 1910 (17), 534. 



" Wien. klin. Woch., 1912 (25), 1698. 



