Table of Contents
Definition / general | Clinical features | Case reports | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosisCite this page: Sangle, N. Chronic pyelonephritis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/kidneychronicpyelo.html. Accessed February 17th, 2019.
Definition / general
- Chronic tubulointerstitial inflammation and renal scarring with severe involvement of calyces and pelvis
- Pyelocalyceal damage / blunting rules out other tubulointerstitial inflammation
Clinical features
- Causes 10% - 20% of end stage renal disease in transplant or dialysis units
- Associated with pyelitis and ureteritis cystica
- Some patients with pyelonephritic scars develop focal and segmental glomerulosclerosis with proteinuria in nephrotic range, perhaps due to renal ablation nephropathy
- Types: reflux (chronic reflux-associated pyelonephritis) and obstruction (chronic obstructive pyelonephritis)
- Reflux: more common, usually arises in childhood, unilateral or bilateral; damage often due to infection; associated with calyceal dilation (usually upper pole); see tubular atrophy and thyroidization, interstitial fibrosis
- Obstruction: associated with parenchymal scarring, usually not in children
Case reports
- 68 year old woman with renal sinus mass by imaging (J Med Case Rep 2009;3:9054)
Gross description
- Irregular scarred cortical surface usually at poles, dilated and blunted calyces
- Dilated ureter; retraction and destruction of papillae with "U” shaped scars
Microscopic (histologic) description
- Tubular thyroidization (filled with colloid casts), tubular atrophy
- Interstitial fibrosis and inflammation (intense diffuse lymphoplasmacytic inflammatory infiltrate with germinal centers)
- Obliterative endarteritis of vessels, interstitial Tamm-Horsfall protein (amorphous, fibrillary, PAS+ material surrounded by inflammatory cells)
- Normal glomeruli early in disease course
Differential diagnosis
- Chronic glomerulonephritis: diffusely scarred cortex
- Vascular disease: can cause wedge-shaped cortical scars, but underlying medullary and calyceal areas are normal