Fig. 1

The patient’s renal pathology report showing a granular C3 deposition mostly in the mesangial area on the frozen section (× 200), b κ light chain negativity in the glomeruli and tubular epithelial cells on the frozen section (× 200), c stronger background staining for λ light chain than κ (yellow arrow) and massive λ reabsorption granules in the cytoplasm of tubular epithelial cells (red arrow) on the frozen section (× 200), d moderate mesangial proliferation (black arrow) (× 400, PASM+Masson), e mesangial electron-dense deposition (red arrow, × 8000), and f abnormal lysosomes in the cytoplasm of proximal tubular epithelial cells (red arrow, × 15,000)