Diffuse coical necrosis, as described in this patient, is usually seen in the setting of disseminated intravascular coagulation, typically in the context of overwhelming sepsis. It can also be seen following hypotension combined with vasoconstriction. Multiple myeloma is associated with renal deposition of amyloid protein and damage to both glomeruli and tubules. Adult polycystic kidney disease would produce enlarged kidneys filled with cystic masses. Pyelonephritis would produce inflammation, often most severe in the renal pelvis. Ref: Levi M., Seligsohn U. (2010). Chapter 130. Disseminated Intravascular Coagulation. In J.T. Prchal, K. Kaushansky, M.A. Lichtman, T.J. Kipps, U. Seligsohn (Eds), Williams Hematology, 8e.