634 



THE UE1VARY ORGANS. 



marked feature of the lesion, the cortex may be reddish or mottled red 

 and yellow. Such are the so-called large red kidneys. 



Arterio-sclerosis and cardiac hypertrophy frequently accompany this 

 type of kidney lesion. 



Interstitial Type of Chronic Diffuse Nephritis. The type of chronic dif- 

 fuse nephritis in which the growth of interstitial tissue is conspicuous, 

 which may be called the interstitial or indurative type, apparently some- 

 times represents a later phase of the parenchymatous type ; or it may re- 

 sult from chronic congestion, or be associated with arterio-sclerosis ; but 



it appears to be more fre- 

 quently an independent proc- 

 ess. As the new interstitial 

 tissue which is formed in 

 patches or streaks or large 

 masses gradually becomes less 

 cellular, more dense, and 

 shrinks, the kidneys are 

 usually smaller than normal 

 and, owing to the uneven dis- 

 tribution of the lesion, rough 

 upon the surface when the 

 thickened and adherent cap- 

 sule is stripped off. The 

 areas of the cortex in which 

 the fibrous tissue is most 

 abundant (Fig. 395) are 

 grayish or translucent and de- 

 pressed, while the parenchy- 

 ma between, often fatty, pro- 

 jects as yellowish rounded 

 knobs or granules. This con- 

 dition is therefore sometimes 

 spoken of as "granular atro- 

 phy," and such kidneys are 

 often called "granular kid- 

 neys " or " atrophied kid- 

 neys. " The tissue is firm and 



resistant to the knife ; and on section the cortex is seen to be in general 

 thinned, often extremely so, some portions being much more atrophied 

 than others. Cysts of various sizes may be formed from dilatation and 

 coalescence of tubules. The cortex is usually more involved than the 

 medulla. The fat with which the kidney is surrounded is often largely 

 increased. 



On microscopical examination the new-formed interstitial tissue is 

 sometimes in patches (Fig. 396) or streaks along the course of the in 

 terlobular vessels, with less affected regions between them. In these 

 fibrous portions there may be flattening of the epithelium and various de- 



FIG. 394. CHRONIC DIFFUSE NEPHRITIS PAREXCHYMA- 

 TOCS TYPE. ^, 



Showing a wedge-shaped mass of new-formed tissue ex- 

 tending inward from the capsule of the kidney, to which it 

 is firmly attached. The tubules within the fibrous area are 

 atrophied, while the tubules elsewhere show various degen- 

 erative epithelial changes. 



