Intracaval liver with cardiac extension. A new developmental anomaly?

Inferior vena cava (IVC) obstruction is uncommon in children. We report a patient with liver within a IVC extending to the right atrium who underwent successful surgical resection. A 12-year-old boy with an Arnold Chiari malformation was admitted for seizures. Premature ventricular contractions prompted an echocardiogram. This revealed a pedunculated mass in the right atrium and an IVC producing turbulent flow. He underwent a mass excision that was continuous with the liver. Histology demonstrated normal liver parenchyma. Based on the embryologic intimacy between the caudate lobe and the IVC, we postulate that the ectopic hepatic nodule was due to aberrant migration of hepatocytes into the IVC during embryogenesis.