RUPTURE OF THE CYST INTO VARIOUS ORGANS. 647 



becomes attached to the adjacent organs, now to the intestine or 

 kidney, now to the diaphragm or abdominal wall. 



The inflammation entails further consequences. It leads to ulcer- 

 ation and destruction of the affected parts. The cyst-wall gives way, 

 and the Ecliinococcus protrudes like a hernia to a varying extent. The 

 diverticulum reaches spaces which were previously shut off from the 

 worm. In the one case it is perhaps the abdominal or thoracic cavity 

 which receives them ; in the other, it is the intestine or the lumen of 

 a vessel, according to circumstances. 



If the diverticulum be but small, and the cavity into which it has 

 penetrated be surrounded by close and resistant walls, so that there 

 is a counterbalancing pressure, then the worm retains for a lengthened 

 period its original character. It fills the cavity, penetrating to an 

 ever-increasing extent. This is most frequently the case with the 

 multilocular Ecliinococcus, whose processes penetrate into the ramifi- 

 cations of the bile-ducts, as well as into the portal vein and lym- 

 phatics, and sometimes grow into them in such a way as to suggest 

 that the peculiar form of the Echinococcus is determined by the spaces 

 which it occupies. 



In such cases the anatomical result is very much what we have 

 above described in the case of Echinococcus of the brain, or of the 

 pleural cavity, when it has left its original seat and expanded in the 

 neighbourhood. 



But it is not always so. When, owing to the size and extensi- 

 bility of the newly occupied space, there results a lessening of the 

 resistance to the diverticulum from the cyst, then the latter continually 

 increases, and becomes more distended with fluid and hydatids, until 

 it finally bursts either spontaneously, or in consequence of some 

 external cause, and expels its contents. 



This issue is extremely frequent in the larger Echinococci of the 

 viscera, which are mostly of the hydatid variety. From Neisser's 

 results we see that of 451 cases observed in the liver, the third part 

 terminated thus. The majority opened either into the alimentary canal 

 (forty-five cases), or, after perforation of the diaphragm, 1 into the 

 bronchi (thirty-one). In sixteen cases each the contents were emptied 

 into the body-cavity and pleural cavity, and a breach through the 

 abdominal wall was equally frequent. The large vessels (veins) and 



1 To the cases of this sort, collected by Davaine (loc. cit., p. 440), I may add a new 

 one observed by Professor Blasius. The preparation is lodged in the Anatomical Museum 

 of the University of Halle, and bears the following label : " Pulmo et hepar sutoris 

 40 ann. n. Frauendorf. Inde ex annis 15 ex echinococcis hepatis aegrotus crebris 

 peritonitidis insultibus vexatur, postremis annis echinococcos bile tinctos cum sputis 

 ediclit. Pulmonis dextri lobus inferior echinococcus destructus per diaphragma cum 

 ductu hepatico dextri lobi hepatis anastomosin inivit." 



