476 TUMORS. 



" Combinations of fully developed basis-substance, with partial 

 retention of the embryonal character, are by no means rare ; they 

 involve what is termed the suspicious nature of the tumor. These 

 tumors allow of a prognosis of recurrence after extirpation, or of 

 a gradual change for the worse, when the surgeon, judging from 

 the appearances to the naked eye, has not the slightest idea of 

 the threatening danger. The inflammatory process in even 

 benign tumors may mislead the microscopist in exceptional 

 instances, and it is only by a thorough examination of different 

 parts of a tumor that a correct decision as to its nature can be 

 obtained. The presence of inflammatory elements within the 

 connective-tissue frame of cancer is well known to be decisive of 

 its malignant nature, and the circumstance that such elements 

 are often found on the surface of an extirpated cancer-tumor 

 indicates, on the one hand, that recurrence will rapidly ensue, on 

 the other hand, that such elements play an important part in the 

 new growth of epithelia, characteristic of cancer." 



Secondary Changes. The tissues of tumors are subject to the 

 same pathological changes which we observe in physiological 

 tissues. These changes sometimes deprive a malignant tumor of 

 its malignity, either in part or altogether, and they may occasion- 

 ally result in a spontaneous cure of either benign or malignant 

 tumors. 



Inflammation ensues spontaneously, and after irritation or 

 mechanical injuries from without. The inflammatory process is 

 different here in its results, though not in its aspect, from the 

 rapid new formation of tissue in malignant tumors. It some- 

 times leads to a formation of an abscess in the depth of the 

 tumor, and may terminate, as in physiological tissues, in the pro- 

 duction of a cicatrix. It sometimes causes ulceration i. e., a slow 

 necrosis of the superficial layers or gangrene, with a partial or 

 complete destruction of the tumor. Gangrene may ensue from the 

 weight of a pedunculated tumor, from pressure, traction, etc. 



Hemorrhage occurs most frequently in tumors which are 

 abundantly supplied with blood-vessels, or where the blood-ves- 

 sels are dilated. It may lead to the formation of encysted extra- 

 vasations in the middle of the tumor, the so-called blood-cysts, 

 from the walls of which again a new growth of the tissue of 

 the tumor may arise. Haemorrhage often causes pigmentation of 

 the tumors. Gangrene is sometimes produced after haemorrhage by 

 complete destruction of the tissue, and in this way a cure may 

 follow. 



