Mild unilateral proteinuria and renal vein thrombosis associated with oral contraceptive usage

A previously healthy 15-yr-old female taking oral contraceptives presented with acute, isolated, unilateral renal vein thrombosis as documented by arteriography and venography. Mild proteinuria (760 mg/24 hr) was localized solely to the thrombosed kidney by selective ureteral collections. The case illustrates an oral contraceptive associated renal vein thrombosis in the absence of either inferior vena cava thrombosis, bilateral proteinuria, or the nephrotic syndrome. This patient's proteinuria and clinical course suggest that nephrotic syndrome is a cause of renal vein thrombosis rather than an effect of renal vein thrombosis. The finding of localized, unilateral proteinuria is discussed.