Mycotic aneurysm of the renal artery: CT appearance

Mycotic aneurysms of the renal artery are rare with the diagnosis usually made by angiography (Clark et al, 1972; Kaufman & White, 1978). Computed tomographic diagnosis of abdominal mycotic aneurysms has been discussed (Pripstein et al, 1979), but to date the CT appearance of a renal artery mycotic aneurysm has not been reported. Mycotic aneurysms are uncommon and difficult to differentiate on CT from an aortic dissection with involvement of the renal artery. However, renal artery mycotic aneurysms should be considered, given the appropriate clinical circumstances. We report a case of a pathologically proven main renal artery mycotic aneurysm. A 66-year-old white man was admitted with right lower quadrant tenderness, fever, and leukocytosis. His urinalysis indicated three to five white blood cells per low power field and the rare occurrence of bacteria. He had a longstanding history of chronic urinary tract infections secondary to benign prostatic hypertrophy, and the urinalysis findings were considered his baseline. Blood cultures were drawn on admission. Because of increasing abdominal pain over the next 24 h, a laparotomy with appendicectomy was performed. At surgery the liver, gallbladder, duodenum, and spleen were normal. Microscopically the appendix showed no inflammation. The blood cultures at this point showed no growth.