ECHINOCOCCI OF THE LIVER. 699 



bursts. If the distended and thinned peritoneal covering ruptures at 

 the same time, the contents of the sac enter the peritoneal cavity, and 

 there is severe peritonitis. In the same way, if the sac has become 

 adherent to the neighboring parts, it may be evacuated into the stom- 

 ach, intestines, gall-ducts, neighboring blood-vessels ; or, when the dia- 

 phragm has been gradually thinned, and finally perforated by the 

 pressure, the sac may empty into the pleural cavity or into the lung 

 adherent to the pleura. In still other cases, the hydatid excites in- 

 tense inflammation in its vicinity, particularly in the fibrous envelope be- 

 longing to the liver. This appears to occur particularly in those cases 

 where the sac bursts inside of the liver, and its contents come in direct 

 contact with its parenchyma. In such cases, besides shreds of the 

 mother vesicle, and sometimes single, still perfect daughter vesicles, the 

 cyst contains purulent masses tinged with bile. These cases are evi- 

 dently not due to inflammation of the mother vesicle, but the pus has 

 entered the sac from without. The abscesses of the liver, thus induced, 

 may have any of the terminations described in Chapter IL If it per- 

 forates externally, rudiments of the echinococcus vesicle are mingled 

 with the pus that escapes. 



SYMPTOMS AND COIJESE. As a rule, echinococci inhabit the liver 

 for years before they attract attention, or the disease is suspected. The 

 gradual growth sufficiently explains the absence of inconvenience, or 

 its tardy appearance. In most cases where the disease is recognized, 

 its discovery is not brought about by the subjective symptoms, but by 

 the patient himself, or the physician accidentally noticing that the right 

 hypochondrium is prominent, and contains a tumor. If the hydatid, 

 and with it the liver itself, attain a considerable size, the feelings of 

 pressure and tension in the right side, so often mentioned, are occasion- 

 ally induced. The diaphragm, pressed upward, may have its action 

 interfered with. The compression of the lower lobe of the right 

 lung and the collateral hyperaemia in the non-compressed portions of 

 lung may induce dyspnoea and bronchial catarrh. In the same way, 

 ascites and icterus of variable amount may result from compression 

 of the branches or trunk of the portal vein of the small ducts, or 

 the excretory duct of the bile; but all these symptoms are excep- 

 tional. 



Physical examination is the most important, and in the majority of 

 cases is the sole means of diagnosis. Like large and numerous carci- 

 nomatous tumors, large and numerous hydatids in the liver are also 

 often evident on inspection. In these cases also there is a prominence 

 in the right hypochondrium, extending below the navel, and into the 

 left hypochondrium ; and, while the shape of the swelling reminds lot 

 of the liver, we notice on it slight elevations of different sizes. At the 



