An African American man aged 32 years with newly diagnosed HIV infection presents with rapidly progressive renal failure and nephrotic range proteinuria. Biopsy shows collapse of the glomerular tuft, marked hypertrophy and hyperplasia of visceral epithelial cells filling Bowman space, tubular microcystic dilation with proteinaceous casts, and a striking lack of interstitial edema despite severe tubular injury. Which variant does this represent?

• A Tip lesion variant of FSGS
• B Cellular variant of FSGS
• C Perihilar variant of FSGS
• D Collapsing variant of FSGS ✓

Explanation

HIV associated nephropathy corresponds to the collapsing variant of FSGS, characterized by global wrinkling and collapse of the capillary tuft, prominent podocyte hypertrophy and hyperplasia, tubular microcysts, and rapid progression to ESRD. Strong association with APOL1 risk alleles explains the predilection for individuals of African ancestry. The perihilar variant relates to adaptive responses and hyperfiltration, not viral injury, while tip and cellular variants carry better prognoses.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.