Small hepatocellular carcinoma with intravascular tumor growth into the right atrium

A 66-year-old man with ascites and marked edema in the lower extremities was suspected of having secondary Budd-Chiari syndrome due to primary liver cancer, based on imaging diagnosis, i.e., ultrasonography, computed tomography, and inferior venacavogram. At autopsy, an encapsulated small liver cancer was found to have extended into the inferior vena cava and right atrium. There have been few reports of small hepatocellular carcinoma with intravascular tumor growth into the right atrium.