Accessory renal hilus.

A defect in the renal margin secondary to extrahilar entry of renal vessels was detected at urography in three patients. Extrahilar entry of renal vessels is not uncommon and is well known to anastomists and surgeons. It has not been previously reported as a radiographic finding. In the past these marginal defects may have been assumed to be persistent fetal lobulation or scarring from previous renal infarction or pyelonephritis. Arteriography may be necessary to distinguish between these possibilities and occasionally to exclude a renal tumor or cyst.