314 



TUMORS. 



but are apt to merge into one another and to intermingle in various 

 ways. 



Spindle-celled Sarcoma. The cells in these tumors may be large large 

 spindle-celled S. (Fig. 150) ; or they may be small small spindle-celled 8. 



(Fig. 151). They may consist largely of cells, or may contain so much 

 intercellular fibrous tissue as to be appropriately called fibro- sarcoma. 

 The cells are frequently arranged in fascicles, which surround the blood- 

 vessels, and these fascicles may cross and interlace. These tumors, espe- 

 cially the small-celled forms, are, as a rule, denser and firmer and less 

 malignant than other forms of sarcoma, but to this there are many ex- 

 ceptions. They may be encapsulated or infiltrating. To this class be- 

 long the growths formerly described as fibro-plastic tumors and recurrent 

 fibroids. They frequently occur 

 in the periosteum, subcutaneous 

 tissue, and muscle ; in the uterus, 

 and in various glands, notably in 

 the mamma, testicle, thyroid, etc. 

 These forms are among the most 

 frequent of the sarcomata. 



Round-celled Sarcoma. Of 

 these there are two classes 1, 

 small round-celled sarcomata and, 

 2, large round-celled sarcomata. 



1. The small round -celled sar- 

 comata consist of cells of about 



the size and appearance of monouuclear leucocytes (Fig. 152), and may 

 have much or little intercellular substance, which maybe irregularly dis- 



FIG. 151. SMALL 



SPINDLE-CELLED SARCOMA OF 

 FOREARM. 



