Fig. 1

Tubulointerstitial nephritis and granulomatous vasculitis. (A) Tubulointerstitial nephritis developed with focal but extensive infiltration of inflammatory cells in the tubulointerstitium. (B) Tubulointerstitial nephritis was noted, but glomerular lesions could not be seen. (C) Mononuclear cells including eosinophils (arrowhead) infiltrated the interstitium with mild tubulitis (arrow). (D, E) Non-necrotizing and granulomatous vasculitis developed in interlobular arteries. (F) Infiltration of mononuclear inflammatory cells were found in arterial intima, arterial media (arrowhead), and the arterial adventitia to the perivascular area without fibrinoid necrosis, indicating non-necrotizing and granulomatous arteritis. (A-C) HE stain; (D-F) PAM stain; (A) × 100, (B) × 200; (C, F) × 1,000; (D, E) × 400