506 TUMORS. 



these were represented the varieties called ' ' round-cell sarcoma " ; " spindle-" 

 combined with " round-cell sarcoma" and " alveolar sarcoma." 



The changes in the epithelium, which are induced "by the growth of mye- 

 lomatous tumors, may be divided into two groups. The first embraces the 

 purely inflammatory process; the second includes changes that lead to the 

 production of myeloma elements from epithelium. No distinct boundary can 

 be drawn between these two groups ; for the changes observed in inflamma- 

 tion are like those accompanying the growth of tumors, inasmuch as in both 

 instances new formation of living matter and production of new elements 

 results. 



Inflammatory changes. Specimens of the tumor (1) taken from the integu- 

 ment near the ulceration show, with low power, that the epidermal layer was 

 thinned in several places. (See Tig. 203.) We could see that the pigmented 

 layer which constitutes the border nearest the connective tissue is in a con- 



FlG. 204. FlBRO-MYELOMA FROM THE ABDOMINAL WALL 

 OF AN ADULT. 



D, bundles of connective tissue of derma in transformation to bioplasson; V, blood- 

 vessel ; P\ transformation of pigmented epithelia into non-pigmented plastids; f 2 , epithelia 

 breaking down into pigmented lumps. Magnified 800 diameters. 



dition of moderate " cell-infiltration " that is, inflammation. The pigmented 

 epithelium is arranged irregularly, and is deficient in many places. Higher 

 amplification proves that the epithelium along the connective tissue is broken 

 up into elements, which do not differ from those which originate in connect- 

 ive tissue ; only the pigment is a reminder of their origin, but the pigment in 

 this situation also gradually decreases as the inflammatory changes proceed 

 toward the epithelium. We meet with dispersed pigment granules, or groups of 

 such granules, apparently remnants of former epithelium, though the larger 



