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Chapter XXIII. 

 HYDATIDS m THE UEINAET OEGANS. 



Hydatids in the kidneys are rare ; and only one of 

 these organs is usually affected, in the same individual. 



The cyst is generally single, and the hydatids 

 contained within its cavity are almost always mul- 

 tiple. The walls of the cyst are firm and fibrous, and 

 sometimes even fibro-cartilaginous, or cretaceous ; 

 and its contents luidergo various alterations of struc- 

 ture at different periods of their existence. The 

 hydatid pouch may, in an advanced stage, be occa- 

 sionally arrested in its growth, and its volume may 

 even become so much contracted as to lead to a cure; 

 but, more frequently, it continues to increase in size, 

 and forms a considerable tumour, which produces 

 general or partial distension of the kidney, and more 

 or less complete atrophy of the substance of that 

 organ. The part of the kidney which is occupied by 

 a large-sized hydatid cyst, sometimes assumes a 

 yellowish tint ; and the pelvis of the kidney is, at 

 the same time, connected with the cyst by means of 

 organised false membrane, which is traversed by 

 numerous vessels. 



A section of the tumour usually exhibits the 

 following arrangement : externally, it is formed by 

 the atrophied and anoemic renal substance, which is 

 still distinct in some parts, whilst in others it is 

 reduced to simple areolar tissue, which is infiltrated 

 with yellowish matter ; in the interior, it is seen to 



