Primary Budd-Chiari Syndrome With Right Atrial Extension: A Rare Presentation of Intrahepatic Cholangiocarcinoma.

Budd-Chiari syndrome (BCS) is defined as hepatic venous outflow obstruction and can be classified as primary when the obstruction is due to a predominantly venous process, caused by multiple risk factors that lead to a prothrombotic state. We report a case of a primary BCS, with an exuberant thrombus extending from the supra-hepatic vein, via the inferior vena cava, to the right atrium, a rare form of presentation of intrahepatic cholangiocarcinoma (ICC).