Figure 1.

Drug-induced epithelial cell injury. (A) A glomerulus from a patient treated with pamidronate exhibits collapsing FSGS with global wrinkling and retraction of the glomerular basement membrane associated with swelling and proliferation of overlying epithelial cells. Jones methenamine silver, ×600. (B) In this patient treated for multiple sclerosis with IFN-β, glomeruli appear unremarkable by light microscopy. On ultrastructural evaluation, complete foot process effacement, diagnostic of minimal change disease, is seen (×6,000).