99mtc macroaggregated albumin ( maa ) scintigraphy is always performed before administration of 90y -- microspheres for the treatment of liver tumors for hepatopulmonary shunt calculation . 
 tumor thrombus visualization in the hepatic vasculature is an infrequent finding on the 99 m tc -- maa single photon emission computed tomography . 
 we present a rare case of a hepatocellular carcinoma extending as a tumor thrombus through hepatic vein , inferior vena cava into the right atrium .