632 



THE URINARY ORGANS. 



Parenchymatous Type of Chronic Diffuse Nephritis. This may originate 

 in an acute diffuse nephritis but more frequently develops independently 

 of this. As in other forms of diffuse nephritis, the tubules, the gloni- 

 eruli, and the interstitial tissue are more or less involved. The lesions 

 are most marked in the cortex (Fig. 592), and here the epithelium may 



1 



' -4 H 



FIG. 392. CHRONIC DIFFUSE NEPHRITIS PARENCHYMATOUS TYPE. 



At the left is a band of new-formed flbroiis tissue with atrophy of tubules and swelling and prolifera- 

 tion of the capsule cells ; in the central portions the tubular epithelium is disintegrating at the edges, while 

 at the right the lumina of the tubules are dilated, with flattening of the epithelium. 



be swollen and coarsely granular or is often fatty. Droplets of clear 

 fluid may form within the epithelium so-called "vacuoles." The epi- 

 thelium may be flattened or it may peel off or disintegrate and the cells 

 and cell detritus together with leucocytes, red blood cells, and casts may 

 collect in the irregular and often widened lumiua. The casts may be 

 hyaline or granular or epithelial, or they may be covered with leucocytes 

 or red blood cells. In the glomeruli, the tuft and capsule cells may 

 swell and proliferate and peel off (Fig. 393) ; albuminous fluid which in 

 specimens hardened in alcohol is represented by a granular precipitate 

 may be present in the intracapsular space and in the tubules. The in- 

 terstitial tissue may be increased in amount, usually in circumscribed re- 

 gions, and here the enclosed tubules are atrophied. Not infrequently, 

 more or less extensive haemorrhages occur. 



If the disease have been of long standing the new-formed interstitial 

 tissue may be present in considerable amount with much destruction of 

 the tubules. The glomeruli may be compromised by the thickening of 

 Bowman's capsule and the obliteration of the capillaries, so that at length 

 the tuft and capsule may fuse and the glomeruli may be represented by 



