AJR 2004; 183:1697-1702.
Westphalen A, Yeh B, Qayyum A, Hari A, Coakley FV.
Masses in the perinephric space, including the peripelvic space of the renal hilum, may be due to tumor, fluid, inflammation, or various prolifer-ative diseases. More broadly, abnormal tissue at the periphery of the kidney may be subcapsular or perinephric in origin, and these processes are not always distinguishable, so the differential diagnosis for perinephric masses includes subcapsular disease.
Radiologic evaluation of renal and perinephric masses is increasingly important; for example, more than half of renal cell carcinomas are discovered incidentally during imaging performed for unrelated reasons [1]. The objective of this pictorial essay is to provide a timely review of those diseases that may result in perinephric or subcapsular masses, with an emphasis on key clinical or radiologic differentiating features.