VARIOUS HUMAN SARCOMAS 



119 



decide whether a parasite is inside a cell or a capillary bloodvessel, 

 but this does not apply to the smaller intracellular bodies. The 

 physical characters, staining reactions, and results of subdivision of 

 these bodies here described as parasites show them to be of the 

 same nature as those in the other two tumours ; but whereas in the 

 sarcomas of the breast and testis multiple division into small bodies 

 predominated, in this instance binary fission and multiple budding 

 are the commoner modes of subdivision. 



a b 



FIG. 47. SARCOMAS OF BONE. (From the Author's ' Surgical Pathology and 



Principles.') 



, Periosteal sarcoma ; b, central myeloid sarcoma. 



Sarcoma of Bone. Two well-defined types of sarcoma occur in 

 bone, the periosteal and the central, as indicated in Fig. 47 ; a and b 

 one a rapidly growing and very malignant tumour, the other a slow- 

 growing tumour, which usually shows but little malignancy. The 

 former arises, as a rule, on the surface of the bone, in the periosteum ; 

 the latter in the central medullary cavity. On these practical clinical 

 features is based a corresponding difference of treatment ; the 



