Diabetic nephropathy , a common sequela of diabetes mellitus, is manifested as severe arteriolar nephrosclerosis, glomerulosclerosis, and acute or chronic pyelonephritis. Diabetic glomerulosclerosis is shown in this slide. This glomerulosclerosis causes proteinuria in 55% of juvenile onset and 30% of adult onset diabetics. It usually presents about 16 years after the onset of diabetes. Diabetic glomerulosclerosis is the result of thickening of the basement membrane of the glomerular capillaries and increased cellularity of the mesangium, along with an increase in the mesangial matrix. The depostion of basement membrane in the mesangial matrix may become so pronounced as to form large nodules of hyaline material and is referred to as Kimmelstiel-Wilson disease which is specific for diabetes mellitus. This specimen shows the Kimmelstiel-Wilson variant of glomerulosclerosis. Note the large hyaline mass in the upper left hand portion of the screen and a smaller one in the center of the specimen.