A 58-year-old woman with 20 years of poorly controlled type 2 diabetes undergoes kidney biopsy for progressive proteinuria. Light microscopy shows large, rounded, eosinophilic, PAS-positive acellular nodules within the glomerular tufts. These nodules represent:
- A Subendothelial immune complex deposits
- B Necrotising granulomas centred on the glomerulus
- C Accumulation of mesangial matrix material ✓
- D Proliferation of parietal epithelial cells forming crescents
Correct answer: C. Accumulation of mesangial matrix material
Explanation
Kimmelstiel-Wilson nodules are ball-like accumulations of mesangial matrix, PAS positive and acellular, characteristic of advanced diabetic nodular glomerulosclerosis. They are accompanied by diffuse GBM thickening and hyaline arteriolosclerosis of both afferent and efferent arterioles. Immune complex deposits define lupus or MPGN, and crescents indicate rapidly progressive glomerulonephritis, none of which fits this histology.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.