Mild luminal dilation and loss of nuclei is evident in acute tubular necrosis.

Sloughed necrotic epithelial cells are filling the tubular lumens.

Another tubule shows similar findings. Note the patchy nature of the process, with relatively intact tubules adjacent to the severely injured one.

Recently necrotic epithelial cells appear as pink amorphous blobs in the wall and lumen of the tubule. The adjacent tubules show simplification with cystic change.