XVII. 



TUMORS. 



May be defined to be hypertrophies or over-growth, and are of 

 great variety. A tumor differs from an inflammatory exudate, in 

 that it increases in itself, and grows as a part of the body by its 

 own adherent force, depending on the surrounding parts for little 

 more than a supply of blood, from which it appropriates its 

 nourishment. As a rule, a tumor increases constantly, whereas 

 an inflammatory exudation depends upon a morbid state of the 

 parts, and increases in size only so long as the morbid action con- 

 tinues. • 



A tumor rarely actually disappears, and thus differs from an 

 inflanmiatory growth. They usually develop from small begin- 

 nings. Some grow rapidly, others slowly and intermittently, and 

 there is no limit to their growth, some reaching enormous size. 

 They deprive the organ on which they are placed of nutriment, 

 and are attended with more or less inconvenience or danger. 

 We speak of a tumor as being malignant when it has a tendency 

 to destroy and infiltrate into surrounding tissues; when it tends 

 to recur after removal, and where there is no healing. The most 

 common forms of tumor met with in the lower animals are fibrous 

 tissue tumors, fibromata, and ordinar\^ warts. 



FIBROUS TUMOR. 



The fi])roma, or fibrous tumor, is slow in growth, and is not 

 accompanied by pain or tenderness; is of a hard, rounded form; 

 generally movable, and contained in a wall of areolar tissue. An 

 example of this is a fibrous tumor between the neck and point of 

 the shoulders, caused by the collar. . When cut into, it will be 

 found to have thickened walls containing a little pus. This old 

 abscess may be removed by excision of the whole mass. If they 



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