When "diabetic nephropathy" is not always of diabetic origin: a case report.

The etiology and pathogenesis of fibrillary glomerulonephritis (FGN) remains unknown. The presented case shows an extremely rare FGN in association with commonly diagnosed diabetes. A 74-year-old, non-smoking, obese and diabetic woman was hospitalized due to a progressive and accelerated decrease in the renal function. The primary cause of chronic kidney disease was believed to be of diabetic origin. In the renal biopsy, light microscopy showed glomerular changes resembling diabetic nephropathy, however electron microscopy evaluation revealed linear, randomly arranged fibrils present in the glomerular mesangium and in peripheral capillary loops. The biopsy confirmed fibrillary glomerulopathy.