3CJ 



VETERINARY PATHOLOGY. 



in structure. Degeneration as well as necrosis and calcification 

 are of frecjuent occurrence in myeloid sarcomata. 



These tumors may not be completely encapsulated, though 

 there is always a tendency for them to be circumscribed. They 

 are tlie least malignant of all sarcomata. They rarely form me- 

 tastases. 



Mixed-Cell Sarcoma. — This is a variety of sarcoma charac- 

 terized by the presence of variously shaped cells, as round, spin- 

 dle and even stellate cells. This variety is not as common as 

 either the round-cell or spindle-cell varieties. They have been 

 observed in the horse, hog and ox, but they doubtless occur in 

 all domestic animals. They affect bone, glandular tissue, and 

 lueninges of the brain, in fact, no tissue is exempt. An inter- 

 esting case of mixed-cell sarcoma of the inferior maxilla of a 

 hrirse was described in the December A'eterinarv Review, 1905. 

 The tumors frecpientlv degenerate and become necrotic, ^li- 

 croscopically tliev are composed of round cells and spindle 

 cells that are identical in structure with those described in tfie 

 discussion of round-cell and spindle-cell sarcomata. Stellate 

 cells ma)r be present, and are very similar in structure to mucoid 

 connective tissue cells. The cellular elements are supported by 

 reticidar tissue or by fibrous connective tissue. The number of 

 blood vessels is variable. There is an excess of vessels in those 



5*- 



FifT- IGS. — Photop:raph of >Faxilla of horse shown in Fip:. 162, showing 3 bony points; 

 thi.- remaimler nf tliu maxilla boing compirtely drstroyt.>d by the sarcomatous tissue. 



