A 28-year-old male with AIDS presents with moderate proteinuria and hypeension. Histologic sections of the kidney reveal the combination of normal-appearing glomeruli and occasional glomeruli that have deposits of hyaline material. No increased cellularity or necrosis is noted in the abnormal glomeruli. Additionally, there is cystic dilation of the renal tubules, some of which are filled with proteinaceous material. Electron microscopy reveals focal fusion of podocytes, and immunofluorescence examination finds granular IgM/C3 deposits. What is the best diagnosis for this renal abnormality?