Renal Artery Aneurysm Mimicking Nephrolithiasis: A Case Report and Review of Literature

Abstract

While originally described in the 18th century, the incidental detection of renal artery aneurysms (RAAs) has increased significantly with the advent and increased usage of modern cross-sectional imaging. Although the incidence remains low, RAAs are clinically important, especially if measuring greater than 2 cm in diameter. Therefore, ultrasonographers and radiologists alike should be aware of its features on multiple imaging modalities as well as imaging pitfalls. Renal duplex sonography is widely used for the evaluation of renal arteries stenosis, fibromuscular dysplasia, renal veins patency, and for the status of renal transplants. RAA is another, albeit rare, indication for renal arteries duplex examination. Furthermore, RAAs may be an incidental finding on abdominal or renal ultrasound. Therefore, familiarity with the sonographic presentation of a RAA is important. Diagnosing RAAs with duplex ultrasound may become exceptionally difficult when the aneurysm has peripheral calcification, even more so when the aneurysm is situated by the renal hilum. Those calcified arterial walls may produce strong acoustic shadowing, mimicking a renal calculus.