A pitfall in diagnosing a tumor thrombus by computed tomography

This paper presents a case of right renal cell carcinoma with a false-positive finding of tumor thrombus in the inferior vena cava. The intraluminal filling defect revealed by computed tomography appeared to be an artifact due to the inflow of non-opacified blood into the inferior vena cava. The possibility of such an artifact should be borne in mind to avoid as far as possible any unnecessary diagnostic intervention and delay in instituting proper therapy.