Arteriographic demonstration of extension of renal carcinoma into renal vein and vena cava.

On rare occasions, arteriography of a renal cell carcinoma shows tumor vessels following the course of the renal vein and vena cava. In our cases, surgical exploration and microscopic examination showed that this appearance was due to tumor vessels arising from within the renal tumor and extending intraluminally within the venous system to supply the tumor.