TUMORS. 



349 



structure, which are held together by a more areolar fibrous tissue 

 supporting the larger bloodvessels of the tumor (Fig. 308). Among 

 the hardest of the fibrous new-formations is the keloid, which in 

 its oldest parts resembles old cicatricial tissue, the fibrous inter- 

 cellular substance being compacted into dense, almost homogeneous 

 masses and bands, in which the nuclei of the cells are barely dis- 

 cernible (Figs. 309 and 310). 



Fibromata do not always have a nodular character, even when 

 they are of dense structure. They sometimes occur in a diffuse 



FIG. 311. 



Intralobular fibroma of the breast. (Ziegler.) a, acini and ducts of the gland; 6, new- 

 formed fibrous tissue; c, areolar tissue of the interstitium, containing the vascular 

 supply. 



form, surrounding and enclosing the structures of the organ in 

 which they develop. Such diffuse fibromata of the mammary gland 

 are not uncommon, and two varieties may be distinguished : 1, those 

 in which the fibrous tissue develops between the lobules of the 

 gland, separating them from each other by broad bands of dense 

 character, the interlobular form ; and, 2, the mtralobular form, in 

 which the individual acini of the gland are separated and sur- 

 rounded by bands of fibrous tissue (Fig. 31 1). These diffuse fibrom- 



