A 45-year-old man with longstanding type 2 diabetes mellitus undergoes renal biopsy for progressive proteinuria. Light microscopy reveals nodular glomerulosclerosis with PAS-positive deposits in the mesangium. This lesion is best described as:

• A Wire-loop lesions of lupus nephritis
• B Amyloid deposits
• C Mesangial IgA deposits
• D Kimmelstiel-Wilson nodules ✓

Explanation

Kimmelstiel-Wilson nodules are pathognomonic of diabetic nephropathy and represent nodular accumulations of laminated matrix material in the periphery of the glomerulus. They stain strongly with PAS and are composed of type IV collagen and laminin. This pattern arises from chronic hyperglycemia-driven mesangial expansion and is the hallmark of advanced diabetic glomerulosclerosis.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.