Fig. 3

Histopathological findings on immunofluorescence and electron microscopy. Immunofluorescence showed a positive linear tubular and glomerular basement membrane staining (3 +) for kappa (A, 20x) and negative for lambda (B, 20x) light chains on formalin-fixed paraffin-embedded tissue. Immunofluorescence staining on fresh frozen tissue was weakly positive (± or 1 +) for kappa (C, 40x) and negative for lambda (D, 40x) light chains. Electron microscopy (E, 14000x) showed foot process effacement with cytoplasm vacuolization and ground-pepper-like subendothelial deposits (arrows)