316 



TUMORS. 



moles of the skin often form the*** Rtorfcmg-pAintfL 1 They belong ^ n tha 

 most malignant of tumors. They very readily form metastatic tumors in 



various parts of the body, which are, like the parent tumor, pigmented. 

 Various forms of tumors may contain brownish pigment deposited in 



m 



& 



FIG. 154. LARGE ROUND-CELLED SARCOMA. 

 A tumor of the mamma. Mltotic figures in some of the cells. 



them by the degeneration of the haemoglobin from extravasated blood ; 

 tEeSershrrnWriobt be mistaken for melanotic sarcomata. 3 



Myeloid or Giant-celled Sarcoma. Tumors of this class are usually 

 formed chiefly of spheroidal or fusiform cells of variable size, but their 

 characteristic feature is the presence of larger and smaller multiuuclear 

 cells, called giant cells. These are closely intermingled with the other 



FIG. 155 MELANO-SARCOMA. 

 Tumor from submaxillary region. 



cells, and may be very abundant or very few in number (Fig. 15G). 

 Giant cells may occasionally occur in other tumors, but are most abun- 

 dant and characteristic in these. These tumors are chiefly formed in 

 connection with bone, and may originate in the marrow or in the peri- 

 osteum. They are sometimes very soft and vascular, and subject to 



1 For bibl. of multiple melano-sarcomata of the skin, see Wilson and Kalteyer, Am. 

 Jour. Med. Sci., vol. cxxvi., 1903, p. 751. 



2 On the occurrence of melanuria in cases of melano-sarcoma consult Thacher, 

 Transactions New York Pathological Society. 1893, p. 105. 



