552 



TUMORS. 



Cysts are the results of a coalescence of alveoli, which is due to an augmenta- 

 tion of serous fluid accumulating in the alveoli, finally rupturing them. As 

 regards their origin and development, there is no doubt about the identity of 

 medullary, colloid, adenoid, and cystic cancer. 



My investigations admit of the following conclusions : 



1. Whereas cancer epithelia are developed from medullary corpuscles, and 

 also connective tissue and smooth muscle-fibers, under certain morbid conditions, 

 break down into these corpuscles, cancer may develop indirectly from connective 

 tissue and smooth muscle-fibers. 



2. Cancer epithelia may return to the medullary stage and reproduce myxoma- 

 tous connective tissue. 



3. The reticulum of living matter, present in myxomatous connective tissue, is 



after the transformation of its basis-substance into colloid material. 



FIG. 229. COLLOID CANCER OF THE LARGE INTESTINE. 



F, connective-tissue frame, crowded with medullary corpuscles ; E, epithelia of cancer 1 , 

 partly or entirely filling the alveoli; M, medullary elements, sprung from epithelia; 8, clus- 

 ter of medullary corpuscles, the center of radiating nucleated fibers, traversing the colloid 

 substance. Magnified 500 diameters. 



4. Colloid and adenoid cancer originate from secondary changes of medullary 

 cancer ; the changes consisting, first, in the transformation of the -contents of an 

 alveolus into myxomatous basis-substance, next, in the further change of the latter 

 into colloid substance. 



5. Cystic cancer is but the result of a more advanced stage of liquefaction of 

 the basis-substance of colloid cancer, accompanied by the formation of a connect- 

 ive-tissue sac the wall of the cyst. 



