Images of the month: Crystalglobulin-induced nephropathy.

We report a patient with chronic diabetes and was referred for recent onset proteinuria. Light microscopy of the renal biopsy specimen showed mildly expanded mesangium with mesangial hypercellularity and segmental sclerosis, features compatible with diabetic glomerulosclerosis. However, crystalglobulin-induced nephropathy with crystal deposit was identified on electron microscopy. Renal biopsy is often performed for diabetic patients who present with proteinuria and light microscopy often shows features of diabetic glomerulosclerosis. Additional information may occasionally be revealed on electron microscopy, altering the subsequent plan of management. © Royal College of Physicians 2020. All rights reserved.