Pathology of the urinary system

b) Gross lesions of GN

 

   ∙ 

acute stage of GN → subtle; the kidneys appear swollen and pale; occasionally, the glomeruli are 

visible as fine red dots; 

   ∙ 

chronic stage of GN → the kidneys are shrunken, with a generalized fine granularity of the cortical 

surface; this stage may end up being indistinguishable from chronic interstitial nephritis. 

   ∙ 

worsening glomerular lesions ultimately lead to severe chronic changes in tubules (atrophy), 

interstitium (fibrosis), and blood vessels → “end-stage kidney”. 

 

c) Microscopic lesions of GN

 

   ∙ 

glomerulonephritis can be classified into three types:  

Proliferative glomerulonephritis

 → increased cellularity resulting from proliferation of 

endothelial, mesangial, and/or epithelial cells; 

Membranous glomerulonephritis

 → thickened GBM, which, paradoxically, can be 

associated with marked proteinuria, probably as a result of changes in the charge and pore 

size of the GBM;