Fig. 2.

Renal histopathological findings of light microscopy. Results of the renal biopsy using light microscopy: a, hematoxylin-eosin stain; b, periodic acid-Schiff stain; c, Masson trichrome stain; and d, periodic acid-Methenamine-silver stain. All images were magnified 60×. Seven of 16 glomeruli indicated complete hyalinization, and the glomeruli with incomplete hyalinization showed partial glomerular collapse (arrow in b). The diagnosis was FSGS because the glomeruli showed lobular and segmental expansion. Vacuolar degeneration of podocytes (arrow in a) and enlarged endothelial cells with a thickened loop were observed, suggesting endothelial injury (arrow head in a). Thrombotic microangiopathy was absent. The mesangial matrix slightly increased, but the number of mesangial cells did not increase (b, c). Periodic acid methenamine silver (PAM) staining showed mesangial interposition-like changes and a duplicated basal membrane (arrow head in d). The endarterium is slightly thickened and the arterioles show partial hyaline consolidation