Abstract
Image diagnosis has recently developed and been possible easily to make the preoper ative diagnosis of tumor thrombus in the inferior vena cava. But the clinical trial for direct observation of tumor thrombus itself has not been done. Recently a fiberscope (CHF-P10) covered with a balloon on its tip was inserted into inferior vena cava, and observed directly tumor thrombus. In two of three cases (renal cell carcinoma and cholangiocefular carcinoma), the tumor thrombus protruding from renal vein or hepatic vein and floating into the inferior vena cava could be clearly observed. In another case (hepatocellular carcinoma), although tumor thrombus had already disappeared, there was an anomaly of left-sided inferior vena cava with intravascular anomalous septum.
