CHAPTER \'II 

 TUMOUR, INFLAMMATORY NEW GROWTH, GRANULOMA 



Tumour. 



' A TRUE tumour or neoplasm is an abnormal non-inflam- 

 matory new growth, composed of newly-formed histological 

 elements, and not the result of a mere transformation of 

 pre-existing normal tissues. Inflammatory new tissue may 

 simulate a neoplasm in being very circumscribed, but inflam- 

 matory new tissue is composed solely of connective tissue 

 and bloodvessels (occasionally bone). On the other hand, 

 a great variety of elements (connective tissue, bone, carti- 

 lage, muscle, gland-cells, etc.) are found m the neoplasmata ' 

 (MacFadyean). 



Surgical Diagnosis. — Tumours must be carefully differen- 

 tiated from other swellings, such as those of inflammatory 

 new growth, hernia;, cysts, and abscesses. From the former 

 the diagnosis can often onl}' be made b)- the aid of the micro- 

 scope, as to all external appearances it looks like a tumour 

 (see Fig. 236) ; from the last three the diagnosis is made 

 by palpation with the fingers and by the general history as 

 gleaned from the owner. As a rule tumours form painlessly 

 — at all events until they attain a certain size. Many of 

 them have definite outlines, whilst some appear to become 

 imperceptibly blended with the surrounding tissues. In the 

 dog and cat they frequently attain an enormous size. They 

 may appear in any region of the body, either externally or 

 internally, and be malignant or benign, single or multiple. 



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