Neoplasms 389 



sions and hemorrhagic extravasations (hematocele) may occur as 

 a result of injury, or secondary to orchitis. 



(2) Pseudo-Cysts. 



(a) Bursae. Synovial Cysts occur in the immediate neighbor- 

 hood of Joints or in the Bursae of Tendons, following acute or 

 chronic traumatic or rheumatic inflammations. 



(b) Contusion and Extravasation Cysts, These include the 

 so-called adventitious bursae or cysts of true neoformation. They 

 are seen in situations where the skin lies in close contact with bony 

 prominences, as on the Elbow, and Digits, particularly in members 

 of large, sluggish breeds, and are due to unusual intermittent pres- 

 sure from lying on hard surfaces. Another familiar form of this 

 cyst is that seen in the Earflap and known as Othematoma but in. 

 this case the contusion is generally so severe as to produce a primary 

 extravasation of blood. Blood in serous sacs does not readily coagu- 

 late, but sometimes a clot forms when it is known as a thrombus. 

 Subcutaneous collections cf extravasated blood rarely suppurate, 

 and if left to Nature sooner or later undergo absorption and organ- 

 ization by a process of reactive inflammation, but during the process 

 the resultant cicatrisation sometimes causes considerable shriveling 

 and deformity. Siedamgrotzky observed the occurrence of a cyst in 

 the subcutaneous tissue extending from the larynx to the left should- 

 er-blade, the development of which followed a bite received by the 

 animal in the neck a week previously. The same authority des- 

 cribed an extravasation hematoma occurring under the serosa of the 

 Bladder, near its neck, which brought about a triple torsion of that 

 organ. Recent, as well as old-standing organized, hematomata are 

 quite commonly found in the Spleen. 



(c) Neural Cysts. These occur as Hydrocephalus and Hy- 

 drorrhacis, leading rapidly to paraplegia, psychic disturbances, coma, 

 or death. The dura is found distended by an accumulation of color- 

 less serous fluid. 



(d) Parasitic Cysts. The varieties of these cysts are fairly nu- 

 merous. They have been found in the Liver, Mesentery, Omentum, 

 Muscular Tissue, etc. 



(e) Emphysematous Cysts. These which are common enough 

 in the Mesentery of the hog, are sometimes seen in the same situa- 

 tion in the dog (Williams). 



