What does this mean? FINAL DIAGNOSIS =- Kidney, right, needle biopsy (DSP-16-26303; 11/7/2016): 1) Focal segmental glomerulosclerosis with glomerulomegaly. 2) Mild mesangial sclerosing glomerulopathy. 3) Severe hypertensive arteriosclerosis. 4) Moderate tubular atrophy and interstitial fibrosis. See comment. Electron microscopy will be reported as an addendum. Commnet =- There is no evidence of a glomerular disease of the immune complex type seen on immunofluorescence. Light microscopy exhibits focal segmental glomerulosclerosis (FSGS) with glomerulomegaly. In the absence of full nephrotic syndrome, secondary FSGS such as due to hypertension is favored over the primary form. Mild mesangial sclerosing glomerulopathy is present. In the absence of a history of diabetes mellitus, this is most likely related to the patient s hypertension and/or smoking. The biopsy also shows severe hypertensive arteriosclerosis and moderate tubular atrophy and interstitial fibrosis. The patient is a 62-year-old white man with a long-standing history of hypertension and chronic kidney disease, stage IV, who recently had an acute worsening of renal function with a creatinine of 3.5 mg/dL (baseline is 2.5). There is no history or diabetes or obesity. The patient quit smoking 4 years ago. Serum albumin is 3.2 g/dL. Urine albumin to creatinine ratio is 2230. The following tests are negative or normal: ANA, ANCA, anti-GBM antibody, C3, and C4. There are 3-8 red blood cells per high power field on urine microscopy. No lower extremities edema was seen on physical exam. Microscopic Description =- LIGHT MICROSCOPY: The sections reveal renal cortex and medulla. There are ten glomeruli, two of which are globally sclerotic. Two glomeruli show segmental sclerosis with increase in mesangial matrix, hyalinosis, and adhesion to Bowman s capsule. The remaining glomeruli appear enlarged and show mild mesangial sclerosis. Peripheral capillaries are patent. Glomerular basement membranes are mildly thickened and show segmental ischemic type wrinkling. No glomeruli with crescents or necrosis are seen. Tubules and interstitium: There is moderate tubular atrophy and interstitial fibrosis involving approximately 40-50% of the cortex sampled accompanied by a mild chronic inflammatory infiltrate composed of predominantly mononuclear cells. There is no significant tubulitis. Tubules exhibit mild acute injury with luminal ectasia and epithelial simplification. Focal interstitial edema is also noted. Vessels: There is severe arteriosclerosis. Arterioles app ear unremarkable. IMMUNOFLUORESCENCE HISTOLOGY: Two glomeruli are sampled for immunofluorescence, one of which is globally sclerotic. There is trace diffuse linear glomerular and tubular basement membrane staining for albumin. Glomeruli are negative for IgA, IgG, IgM, C1q, C3, fibrinogen, kappa, and lambda. Tubular casts stain for IgA, kappa, and lambda.