ACUTE TUBULAR NECROSIS

       At low power, the renal cortex shows coagulative necrosis of several tubules (Fig.1).

      Determine which part of renal tubule is more involved in the process: First, recognize proximal and distal tubules. The proximal tubular cells have more cytoplasm and their nuclei are relatively more close to basement membrane (Fig.2).

      The remaining viable tubules are mainly distal tubules. Therefore, the necrosis mainly affects the proximal tubules. The fact is that, the proximal tubules are more vunerable to injury than distal tubules (Fig.3). 

         Reaction of tubular necrosis is similar to coagulative necrosis else where. Edema and neutrophil infiltration can be seen. This must be differentiated from acute pyelonephritis (Fig.4).

        Hyaline cast is shown (Fig.5).

       Granular cast is shown (Fig.6).