HYDATID TUMOURS. 139 



When the cyst has arrived at a considerable size, it 

 occasions a feeling of distension, of fulness, or of 

 weight rather than of actual pain. This is not the 

 case, however, when the neighbouring parts are 

 attacked by inflammation or suppuration ; pain, 

 wliich is exacerbated by pressure or by motion, is 

 then present, accompanied by rigors, fever, and all 

 the symptoms and consequences of deep-seated 

 suppuration. 



The opening of the tu.mour into a large serous 

 cavity gives rise to immediate and very severe inflam- 

 mation ; when the tumour opens into the vessels, it 

 produces more or less grave disorders, in proportion 

 to the size of the communication between the cyst 

 and the vessels, and the quantity of matter which 

 passes out of the former into the latter. 



If the tumour opens into a mucous cavity, a 

 means of elimination is afforded to the contents of 

 the cyst, which is not unfrequently emptied gradually, 

 and progresses towards a favourable termination 

 without any bad symptoms. 



The ordinary symptoms of hydatids are the 

 existence of a tumour m some part of the body, the 

 phenomena produced by the compression of one of 

 the viscera situated in the same region as the 

 swelling, and the evacuation, either through the 

 natural passages or through an accidental opening, 

 of vesicles or of some portions of the hydatids. 



In the early stages of their development the 

 diagnosis of hydatid tumours is generally very diffi- 

 cult, or even impossible ; but, at a later period, 

 the signs which admit of their being recognised 

 become more evident. 



