Fig. 4

Renal biopsy specimen on light microscopy. Hematoxylin and eosin staining (a; × 400), periodic acid–Schiff staining (b; × 400), and periodic acid–methenamine-silver staining (c; × 400) in light microscopy show an accumulation of eosinophilic and amorphous deposits in the mesangial region (white arrowheads) and part of the capillary walls (white arrows). Direct fast scarlet staining (Panel d; × 400) shows amyloid proteins in the mesangial region (white arrowhead) and part of the capillary walls (white arrow)