Fig. 2
a Light microscopy of the kidneys showing granular deposition in the cytoplasm of renal tubules epithelial cells (H&E stain, 400 ×). b Some renal tubular epithelial cells showed degeneration of mitochondria in the cytoplasm. The size of mitochondria varied, the inner and outer membranes were separated, and the cristae became shorter and disappeared, as observed by electron microscopy (7500 ×). c Electron microscopy of some round granule deposited in lysosomes (7500 ×). d Brown to black deposits in renal tubular epithelial cells, as demonstrated by Timm’s copper staining (400 ×)