Focal segmental glomerulosclerosis; collapsing variant.

*Corresponding author: Dr. Peyman Mohammadi Torbati, Department of Pathology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Telephone: 00982122567222, Fax: 00982122567282, E-mail:[email protected] 1. Case 32 years old male with history of hypertension since three years, and recent illdefined febrile illness was admitted. He has suffered of edema and fatigue. Laboratory examination revealed increased creatinine (8.6 mg/dL), proteinuria (3230 mg/day) and negative secondary work up including HIV serologic test. The patient underwent dialysis followed by renal biopsy in the clinical context of rapidly progressive renal failure. Histopathologic examination revealed positive mesangial immunoreactivity for IgM and C3 in immunoflourescence study. Light microscopic studies disclosed podocytic hypertrophy and hyperplasia that contained prominent intracytoplasmic protein resorption droplets, pseudocrescent formation, wrinkling of the glomeular basement membrane (GBM) and lobular collapse, at least in one of the glomerulus (Fig. 1;A,B,C). Out of twelve glomeruli, four were globally sclerotic. Interstitial fibrosis and cortical atrophy in about ARTICLE INFO