Cancer. 



405 



keratinization, and here, to(\ the change affects the older cellular 

 elements. The interior of the cancer roots show these fiat cells, 

 homogeneous and staining diffusely with eosin or fuchsine, with 

 their nuclei poorly shown or entirely lost, precisely as those of the 

 surface of the epiderm. In consequence on cross section an onion- 

 like concentric lamination of the cells is apparent, with the cells 

 bent in crescentic manner and applied upon each other like flat 



Fig. 122. 



Microscopic section of a sqiiainons epithelioma of urinary lilaclder of cow (low 

 power). Epithelial cords have grown in between the saiootli muscle fibres. 



scales. These horny plugs can sometimes be picked out entire with 

 the knife and are called cancer pearls ["pearly bodies," "squamous 

 cell or concentric nests"]. The arrangement of layers otherwise 

 is apt to be quite irregular, the composite network of epithelial 

 roots forming at places broad, thick masses with wavy outline, at 

 others delicate, line-like threads. 



The stroma of the squamous cell cancer, present in varying pro- 

 portions in dift"erent cases, is usual!}- the seat of a marked round 



