Renal Pathology, Case 4

• The patient is a 69-year-old man with a history of hypertension, diabetes mellitus, type 2, and coronary artery disease. He has known proteinuria and chronic kidney disease. He has no specific complaints.

• BP 150/72; Pulse 60. Heart, lung, and abdominal exams are unremarkable. He has decreased sensation and proprioception of his feet.

• BUN 36 mg/dl• Creatinine 2.7 mg/dl• Hemoglobin A1C 9%

• Urinalysis 3+ protein

Describe the histologic findingsNodular (Diabetic) GlomerulosclerosisThis microscopic section of a solitary glomerulus reveals a large "nodule" of mesangial sclerosis (large arrow). This is the “Kimmeistiel-Wilson” lesion seen in diabetes. There is also evidence of moderate, diffuse mesangial sclerosis (small arrow).

Diabetic GlomerulosclerosisThe electron micrograph of the kidney reveals uniform thickening of all capillary basement membranes. Compare to the previous slide of the histology of the diabetic glomerulus

A – Capillary lumenB – RBCC – Basement membraneD – Epithelial cell

The electromicrograph of the normal kidney reveals three capillaries arranged around the center core of mesangium (asterix). One capillary contains two red blood cells; another capillary contains a neutrophil. The basement membrane is the thin, black line around each capillary. (compare to the basement membrane in diabetic glomerulsclerosis)

A – Foot processesB – RBCC – CapillaryD - Basement membraneE – Neutrophil

Large arrow – Parietal epithelial cell

Small arrow – Visceral epithelial cell