414 THE CHEMISTRY OF TUMORS 



found in a number of tumors leucin, tyrosin, tryptophan, pro- 

 teoses (biuret reaction), and in one glycocoll. Because of the 

 deficient circulation in the tumors, the ammo-acids accumulate 

 in the cancer tissues in sufficient amounts to be detected, and 

 may be found even when no macroscopic evidences of degen- 

 eration are present. Possibly on account of this poor absorption 

 no proteoses, peptones, or amino-acids could be found in the 

 urine of cancer patients by Wolff; 1 but Ury and Lilienthal 2 

 found a positive reaction for albumose in the urine in about two- 

 thirds of all carcinoma cases examined by them ; however, it 

 may be absent even in advanced stages. Petry 3 states that in 

 normal mammary glands all the nitrogen is in a coagulable 

 form, whereas in sarcoma but 13 per cent, is coagulable. This 

 non-coagulable nitrogen is partly in the form of proteoses and 

 peptones, partly as substances not giving the biuret reaction. 



(2) Other Organic Constituents. These, in general, 

 resemble the organic constituents of the tissue from which the 

 tumor arises, for a structural resemblance to the parent tissue 

 always exists, and as structural features depend largely on the 

 proportion of the chemical components, a structural similarity 

 fairly implies a chemical similarity. For example, adrenal 

 tissue contains much fatty material, especially lecithin and cho- 

 lesterin, and hypernephromas show a similar composition ; Gatti 4 

 noted that the proportion of lecithin in a hypernephroma is 

 similar to that in the adrenal ; the fat of a lipoma is, in its 

 qualitative features, almost identical with the normal fat of the 

 same individual ; tumor melanin shows no characteristic chem- 

 ical distinction from normal melanin, etc. 



Glycogen has been particularly studied in tumors, especially 

 because of the erroneous idea advanced by Brault that the quan- 

 tity of glycogen is in direct proportion to the malignancy. From 

 a summary of all the evidence, it seems that two chief factors 

 determine the presence and amount of glycogen in tumors. 

 One is the embryonic origin of the tumors ; thus tumors of 

 cartilage, striated muscle, or of squamous epithelium, which 

 tissues normally contain much glycogen, are likewise provided 

 with an abundance of this material. Second, the occurrence of 

 areas of impaired cell-nutrition favors the accumulation of 

 glycogen in the degenerating tumor-cells, just as it leads to a 

 similar accumulation in all other tissues (Gierke 5 ). The most 

 extensive consideration of this topic is reported by Lubarsch, 6 



1 Zeit. f. Krebsforschung, 1905 (3), 95. * Virch. Arch., 1897 (150), 417. 



2 Arch. f. Verdauungskr., 1905 (11), 72. 5 Ziegler's Beitr., 1905 (37), 502. 



3 Loc. tit. 6 Virchow's Arch., 1906 (183), 188. 



