Sarcojiia. 369 



are usually derivatives of the marrow or periosteum where they 

 occur normally (known as myeloplaxes). They differ from the 

 degenerative types of giant cells (formed in tubercles and about 

 foreign bodies) in the fact that their nuclei are not located about 

 the periphery but are scattered well .in the interior and all through 

 the cell protoplasm ; but all sorts of variations may be found (com- . 

 pletely divided or wreath-like clumping of the nuclei, giant nuclei, 

 eccentric dividing forms, budding nuclei). The number of nuclei 

 in one cell may reach not merely a dozen or two, but hundreds. 

 The cells, whose dimensions may exceed ten to thirty times that of 

 a white blood corpuscle, are irregularly rounded, their margins 

 jagged, are flattened out like large fibroblasts and are often vacuo- 

 lated with fat droplets. In addition to the giant cells there are 

 usually numerous round and spindle shaped cells in the tumor, and 

 a rich supply of capillary vessels from which blood extravasations 

 are frequently found in the tissue, and which give the tumor a 

 dark-red or brownish-red color. From its medullary origin the 

 giant cell sarcoma is often called a iuycIoi:;ciious sarcoma or 111 ye- 

 loma; and when a homogeneous intercellular substance is present, 

 becoming calcified and forming cartilaginous islands or bony tra- 

 becula. the combined appearances are denoted by the terms osteoid 

 sarcoma and osteochondrosarcoma. 



The stellate or reticular cell sarcoma (sarcoma sfellocelluhve) 

 is characterized by highly branched cells forming an intricate mesh- 

 work, usually enclosing between their projections a mucoid, glass- 

 like intercellular material, giving to the growth characteristics 

 commonly indicated by the term myxosarcoma. 



The polvmorphoeellular sarcoma (sarcoma mi.vfoccllulare) is a 

 name given to tliose connective tissue tumors whose cellular con- 

 stituents follow no one cellular form, but are made up of a con- 

 fused mixture of round, spindle, stellate and giant cells, or the bulk 

 of whose cells are elements of variable form, irregularly polygonal, 

 enclosed in a comparatively small amount of intercellular matrix. 



The morphological appearance of sarcoma cells, the size and 

 polygonal shape of their cellular substance and their alveolated 

 arrangement make it often very difficult to determine to which of 

 the classes of sarcomata described and specially named by differ- 

 ent authors a given sarcomatous neoplasm should be referred. 

 This difficulty and the lack of finality in our histogenic basis of 

 classification are apparent in the frequent employment of combined 

 names indicating the mental uncertainty of the pathologist, as sar- 

 coma carcinomatodes, or carcinoma sarcomatodes: and it is not an 



