Haematuria without diagnosis? Think about the rare causes

We describe a case of a 17-year-old man admitted in the emergency room with a 2-month history of intermittent macroscopic haematuria and left lumbar pain. Physical examination and vital signs were normal. Investigation indicated a recurrent non-glomerular haematuria. The Doppler ultrasound revealed a compression of the left renal vein with upstream dilatation which was subsequently confirmed by CT angiography. These findings are in keeping with a case of nutcracker syndrome (NutS). Although asymptomatic in most cases, it can be a rare cause of haematuria. The teenager was referred to paediatric nephrology and was treated conservatively with spontaneous resolution of macroscopic haematuria. With this case, we would like to highlight that in children or adolescents with haematuria without an apparent cause, a high level of suspicion and appropriate imaging are necessary for the diagnosis of NutS.