[Report of a case of a renal arteriovenous malformation presenting an unusual computed tomographic finding]

A fifty-three-year-old woman was admitted for gross hematuria and left lumbago. She was diagnosed as having left renal arteriovenous malformation (AVM) by renal angiography, but contrast enhanced CT of her left kidney demonstrated a low density area of renal parenchyma adjacent to AVM. Because a renal tumor could not be denied completely, we performed translumbar nephrectomy. No renal tumor was found in the removed kidney, and she was diagnosed as having cirsoid type AVM of the left kidney. The low density area in contrast enhanced CT was suspected to be indicating the ischemic renal parenchyma due to the steal phenomenon of renal AVM. This is the first report of a renal AVM with ischemic renal parenchyma demonstrated by CT.