Fig. 1

Representative images of renal pathology. A The first biopsy: Homogenous amorphous material was noticed in segmental mesangium, blue with Masson stain, and positive for Congo red (black arrow). EM examination showed focal deposit of randomly disposed, non-branching fibrils (9.2–10.0 nm) involving epithelial zones (red arrow). B The second biopsy: Beside the same homogenous amorphous material (black arrow) seen in the first biopsy, glomerulosclerosis was observed (black arrow head). EM examination also indicated focal deposit of randomly disposed, non-branching fibrils (10.0 nm) predominately involving epithelial zones (red arrow).