Renal-limited necrotizing granulomatous vasculitis in a pediatric patient

A 10-year-old girl presented with mild proteinuria and hypertension. Laboratory data indicated slightly elevated serum creatinine (0.67 mg/dL) and elevated serum IgG (2111 mg/dL). On renal arteriography mild stenosis over the entire length of the right renal artery and irregular stenosis of the interlobar arteries in the right kidney were seen. She was diagnosed with renovascular hypertension, and received conventional anti-hypertensive therapy, but did not respond to them. The right kidney had atrophy and dysfunction on technetium-99m-labeled dimercaptosuccinic acid renal scintigraphy, and was therefore resected. Histopathology of the kidney indicated severe necrotizing granulomatous vasculitis affecting the arteries from the renal hilus to the interlobar area. After nephrectomy plus steroid pulse therapy, blood pressure and urinary protein returned to normal. To our knowledge, this is the first report of necrotizing granulomatous vasculitis limited to the medium-sized renal arteries.