Electron Microscopy in the Analysis of Renal Biopsies: Always the Last Step?

Electron microscopy (EM) plays a key role in the evaluation of renal biopsies. It is typically regarded as the final step in a diagnostic sequence that begins with light microscopy (LM) and immunofluorescence microscopy (IF). Since LM and IF frequently provide considerable information about a biopsy, consideration is occasionally given to dispensing with the terminal EM examination. In many instances, this would lead to loss of critical information, including the precise location, consistency, and substructure of immune deposits detected by LM/IF as well as a wide array of features that are invisible by optical microscopic methods [1]. It has been estimated that EM provides important diagnostic information for 50% of renal biopsies, even when it brings up the rear in the analytic process [2].