516 THE CUEMIKTRV OF TUMORS 



sium; if iinderfjoin<y much retrogression, little potassium and a larger 

 amount of calcium (Beebe, Clowes and Frisbie). On account of the 

 extensive disintegration, the products of autolysis are usually much 

 more abundant than in benign tumors. The composition varies 

 greatly with the origin, although to a less extent than with the benign 

 tumors. In Fraenkel's laboratoiy ''^ it was found that cancers are 

 often defective in tryptophane, and from a squamous cell carci- 

 noma of the skin little or none of this amino-acid could be ob- 

 tained, although normal squamous epithelium is rich in trypto- 

 phane. Fasal,*^" however, found usually a high tryptophane figure in 

 cutaneous epithelioma, but very irregular results in other tumors. 

 As Bang and Beebe have shown, the tumors arising from h'mphatic 

 tissues show the chemical characteristics of these structures, and con- 

 tain histon nucleinate. Tumors from squamous epithelium develop 

 keratin in direct proportion to the amount of maturity the cells 

 reach. Even the most complex and specific products of metabolic ac- 

 ti\aty may be developed by malignant tumors (e. g., thyroiodin, 

 epinephrin, bile), and in a form and condition capable of performing 

 function. As Buxton has shown, malignant tumors produce a great 

 variety of intracellular enzymes. The idea that glycogen is present 

 in tumors in proportion to their malignancy has been disproved by 

 Lubarsch, Gierke, and others; among the malignant tumors glycogen 

 is found particularly in chorioepitheliomas, hypernephromas, and 

 squamous cell carcinomas. Of particular importance is the observa- 

 tion of Beebe, that the composition of metastatic growths is modified 

 by the organ in which they are growing, so that they tend to resemble 

 the organ serving as their host ; which, however, does not hold for 

 certain of their enzymes (Wells and Long). In a case of primary 

 carcinoma of the liver, "Wolter "^ found the tumor tissue richer in 

 nuelein phosphorus and poorer in phosphatids than the adjacent liver 

 tissue; cholesterol was 0.25 per cent, of the fresh weight, fatty acids 

 1.67 per cent, and water 82.33 per cent., the water of the normal 

 tissue being 79.34 per cent. 



As to the special varieties of malignant growths, there is little as 

 yet determined concerning their chemistry beyond what has been 

 stated above. Their variations in composition are largely the direct 

 result either of their resemblance to some normal tissue or of degen- 

 erative changes that they have undergone. 



"Colloid" carcinoma may be mentioned specially, in view of the 

 confusion caused by the lax use of the term "colloid" {q. v.). The 

 fluid contents of colloid cancers of the gastro-intestinal tract are 

 usually chiefly epithelial mucus, containing mucin mixed with a 

 greater or less quantity of proteins from degenerated cells and serous 



4TWion. klin. Woch.. 1912 (25). 1041. 

 47ar?iorhom. Zoit,.. 191.3 f.').5). SS. 

 ivb Biochem. Zoit., 1913 (55), 260. 



