Case 1, image 1: This was a 56 year old man who died of end stage liver disease. Pyelonephritis was also a finding at autopsy.

Case 1, image 3: Note the cast of inflammatory cells within a dilated renal tubule.

Case 1, image 2: Lots of inflammatory cells within the interstitium. There are scattered lymphocytes in nephrosclerosis, but the inflammation in pyelonephritis is much more vigorous.

Case 2, image 1: This 78 year old man died of complications of blunt force head injury. Hypertensive intracerebral hemorrhage was a significant contributing condition, as it led to his fall and subsequent head injury. He also had changes associated with his terminal decline including pneumonia and Proteus mirabilis sepsis.

Case 2, image 2: His kidneys demonstrated abscesses.

Complications of pyelonephritis can include emphysematous pyelonephritis (which has a high mortality rate), sepsis and acute renal failure.