[Clinical case of the month. Nutcracker syndrome in association with a painful nephrologic disease].

Compression of the left renal vein between the aorta and the superior mesenteric artery causes a physiological condition, the so-called nutcracker phenomenon, but it can sometimes lead to left venous hypertension, or "nutcracker syndrome". Classical manifestations of which are an association of left flank pain, unilateral proteinuria and unilateral hematuria, without renal impairment. We report an atypical association of nutcracker syndrome with IgM nephropathy.