THE URINARY ORGANS. 



641 



unchanged, or there may be developed suppurative pyelonephritis or 

 chronic diffuse nephritis. 



PERINEPHRITIC SUPPURATION. 



t The loose connective tissue about the kidney may become the seat of 

 suppurative inflammation. This may follow mechanical injury or may 

 be secondary to suppurative or other inflammatory processes, such as 

 carjes of the spine, einpyerna, pelvic cellulitis, puerperal parametritis, 

 perityphlitls, and suppurative nephritis. It may be associated with 

 acute infectious diseases in children. The suppuration may extend back- 

 ward through the muscles ; downward into the iliac fossa, the perineum, 

 the bladder, the scrotum, or the vagina ; forward into the peritoneal cav- 

 ity or the colon ; or upward through the diaphragm. 



The kidney itself may be simply compressed by the abscess or be- 

 come involved in the suppurative process. 



CYSTS IN THE KIDNEYS. 



Cysts are formed in the kidneys both during intra-uterine and extra- 

 uterine life. 



Congenital Cystic Kidneys are often striking objects. Either one or 

 both kidneys may be greatly 

 enlarged and converted into a 

 mass of cysts (Fig. 402). The 

 cysts are of various sizes and 

 are Separated from each other 

 by fibrous septa or compressed 

 kidney tissue. They may con- 

 tain a clear yellow, acid thud 



holding in solution the urinary v% ^^^J^X *'"*"' 



salts ; or the fluid is turbid and ; 1F_- ^ffctv * 



brown, and contains blood, 

 uric-acid crystals, and choles- 

 terin. The cysts are often 

 lined with a single layer of flat, 

 polygonal cells. Some of them 

 seem to be formed by a dilata- 

 tion of the tubules and of the 

 capsules of the Malpighian 

 bodies. As causes for such 

 dilatations there may be found 

 obliteration of the tubes in the 

 papillae, and stenosis of the 

 pelvis, ureters, bladder, or ure- 

 thra. Other congenital mal- 

 formations are often associated 

 with this. 



Cysts of the Kidney in the 

 41 



FIG. 402. CONGENITAL CYSTIC KIDNKY. 



Only very small portions of the kidney tissue remain, 



crowded between the cysts. 



