Electron Microscopy in Renal Biopsy Interpretation: When and Why It Still Matters

Area of Science:

• Nephrology
• Pathology
• Electron Microscopy

Background:

• Electron microscopy (EM) provides essential ultrastructural details for diagnosing glomerular diseases.
• It complements light microscopy (LM) and immunofluorescence (IF) in renal pathology.
• EM's role is vital in refining histopathological diagnoses.

Purpose of the Study:

• To review the diagnostic applications of EM in various glomerular diseases.
• To emphasize EM's value in confirming and classifying kidney pathologies.
• To highlight EM's continued relevance alongside newer diagnostic tools.

Main Methods:

• Review of diagnostic applications of EM in major glomerular disease categories.
• Analysis of EM's role in visualizing deposits and ultrastructural changes.
• Comparison of EM findings with LM, IF, and genetic testing.

Main Results:

• EM visualizes deposits in membranous nephropathy and immune complex glomerulonephritides (e.g., IgA nephropathy, lupus nephritis).
• EM differentiates C3 glomerulopathies and identifies pathognomonic findings in hereditary nephritides (e.g., Alport syndrome).
• EM aids in diagnosing fibrillary/immunotactoid glomerulopathies and diabetic glomerulosclerosis.

Conclusions:

• EM remains indispensable for diagnosing glomerular diseases, offering critical ultrastructural insights.
• It validates immunopathologic interpretations and guides clinical management.
• EM's diagnostic utility persists despite advances in molecular and serologic methods.