TUMORS. 485 



omatous character is caused by the reticular arrangement of the 

 usually delicate bundles of connective-tissue fibers, which at the 

 same time inclose in their meshes -a gelatinous, apparently homo- 

 geneous, myxomatous basis-substance, with single plastids, hav- 

 ing the appearance of nuclei. The fibrous character is produced 

 first by the circumstance that the reticulum is composed of a 

 number of fibrillae, in the midst of which delicate rod-like or 

 spindle-shaped plastids are found, and secondly, by an inter- 

 lacing of dense bundles with bundles which are loose and deli- 

 cate. (See Fig. 186.) 



Tumors of this kind often exhibit a transition from the 

 myxomatous to the fibrous structure; in addition to this they 



I 



FIG. 186. MYXO-FIBROMA, GROWN BENEATH THE SCAPULA 

 OF A WOMAN. 



Bundles of fibrous connective tissue in a reticular arrangement. The spaces contain 

 either bundles, O, in an oblique or a transverse section, or a mucoid basis-substance, holding 

 mostly central plastids, P. Magnified 600 diameters. 



sometimes abound in fat-globules, thus assuming the character 

 of lipoma. Myxo-fibroma is a common tumor in the skin and 

 the mucous membranes. Bulky, folded masses of the skin, 

 occurring in the face, on the chest, and the posterior aspect of 

 the body, the so-called leontiasis, belong to this class. It is of 

 somewhat rarer occurrence in the female breast, in internal 

 organs, and as a periosteal growth. 



