Fig. 1

a Some glomeruli show segmental or global glomerulosclerosis (periodic acid–Schiff stain, ×400 magnification). b Fine needle-shaped crystalline structures in proximal tubular epithelial cytoplasm, which were negative for periodic acid-Schiff staining (Masson’s trichrome stain, ×400). Crystalline deposition was observed in podocytes (c) and proximal tubular epithelial cells with many large and abnormal lysosomes (d). The morphology of the crystalline structures was diverse and ranged from a needle shape to a rhomboid shape (electron micrograph, original magnification: c, ×5,000; d, ×6,000)