Histopathological Examination of Clustering Microspheres and Podocyte Infolding in the Glomerular Basement Membrane Using Low-vacuum Scanning Electron Microscopy

Podocyte infolding (PI) in a thickened glomerular basement membrane (GBM) is a rare pathological finding in electron microscopy (EM). We histopathologically evaluated a 57-year-old Japanese male patient with clustering microspheres and PI in the GBM. EM showed clustering microspheres in irregularly thickened GBM and PI into the GBM. Endothelial cells also invaded the GBM on EM. Low-vacuum scanning EM revealed numerous openings or holes in the GBM. Careful examination by EM is needed to identify further cases of clustering microspheres and PI. It is also important to explore these cases using new approaches such as low-vacuum scanning EM.