What are the key biopsy findings in PSGN?

What are the key biopsy findings in PSGN?

• A. Crescents, subepithelial deposits (humps), and mesangial deposits on EM
• B. Membranous thickening
• C. Focal segmental sclerosis
• D. Normal biopsy

Answer: (C)

Poststreptococcal GN is an immune complex–mediated glomerulonephritis. On biopsy, light microscopy shows diffuse proliferative, hypercellular glomeruli with inflammatory cells. Immunofluorescence reveals a granular, “lumpy-bumpy” pattern due to IgG and C3 along the glomerular basement membrane and in the mesangium. Electron microscopy demonstrates subepithelial immune complex humps, the hallmark deposit finding. Crescents can appear in more severe or rapidly progressive cases, but they are not the defining feature. This combination distinguishes PSGN from other patterns like membranous thickening, focal segmental sclerosis, or a normal biopsy.

Poststreptococcal GN is an immune complex–mediated glomerulonephritis. On biopsy, light microscopy shows diffuse proliferative, hypercellular glomeruli with inflammatory cells. Immunofluorescence reveals a granular, “lumpy-bumpy” pattern due to IgG and C3 along the glomerular basement membrane and in the mesangium. Electron microscopy demonstrates subepithelial immune complex humps, the hallmark deposit finding. Crescents can appear in more severe or rapidly progressive cases, but they are not the defining feature. This combination distinguishes PSGN from other patterns like membranous thickening, focal segmental sclerosis, or a normal biopsy.