Editing Pyelonephritis (section)

====Acute pyelonephritis====
Acute pyelonephritis is an [[exudate|exudative]] [[Pus|purulent]] localized [[inflammation]] of the [[renal pelvis]] (collecting system) and kidney. The [[Nephron|kidney parenchyma]] presents in the interstitium abscesses (suppurative [[necrosis]]), consisting in purulent exudate (pus): neutrophils, fibrin, cell debris and central germ colonies (hematoxylinophils). Tubules are damaged by exudate and may contain neutrophil casts. In the early stages, the [[glomerulus]] and vessels are normal. Gross pathology often reveals pathognomonic radiations of [[bleeding]] and [[Pus|suppuration]] through the renal pelvis to the [[renal cortex]].{{Citation needed|date=June 2011}}