Haematuria and the retro-aortic left renal vein.

The authors present the case of a 10-year-old boy with a 2-year history of intermittent macroscopic haematuria. After exclusion of other causes of haematuria through history, examination and a number of investigations, MRI revealed the finding of a retro-aortic left renal vein, which appeared to be compressed between the aorta and the L3 vertebral body. The retro-aortic left renal vein or 'posterior nutcracker syndrome" is a rare but important cause of haematuria and other manifestations of left renal vein hypertension. A discussion about the implications of this finding in children with symptoms consistent with left renal vein hypertension, and the potential options for management is undertaken.