Budd-Chiari syndrome occurs when there is occlusion of the hepatic vein or the hepatic vein fails to drain into the IVC. This can be caused by thrombosis of the hepatic vein, or by right sided heart failure (causing blood to 'back up' everywhere, but its manifestation through the hepatic vein are all the signs of Budd-Chiari syndrome). Anything that can increase the risk of thrombosis can then increase the risk of Budd-Chiari syndrome. This includes polycythemia vera, a hypercoagulable state. Our patient and PV but missed his appointment two weeks ago. He now presents with scleral icterus, an enlarged liver, and some signs of portal hypertension. Thrombosis of the only anatomical option presented that covers all of this is the hepatic vein ie our patient has Budd-Chiari. Remember that Budd-Chiari will have a "nutmeg liver" appearance on gross pathology.

B) Hepatic cirrhosis- it's entirely possible our patient does have hepatic cirrhosis for unrelated reasons, however the acute onset makes this less likely. C) Pancreatic carcinoma- pancreatic carcinoma obstruction of the common bile duct could cause a 'back up' of bile, ultimately causing some liver damage and scleral icterus. However once again the timing makes this unlikely. D) Portal vein thrombosis- portal vein thrombosis could cause some splenic enlargement and portal hypertension. However, its obstruction would not cause a tender, enlarged liver because it is upstream. E) Primary hemochromatosis- due to a defect in hepcidin production, this iron overload presents with darkened skin, insulin disregulation, hepatic damage (with the potential for hepatocellular carcinoma) and heart disease (restrictive or dilated cardiomyopathy, depending on your source). The only one of these signs that our patient has is an enlarged liver.

found this super useful book on amazon about Budd-Chiari (check out the sick cover)

According to Goljan, polycythemia vera is one of the most common causes of Budd-Chiari syndrome. According to FA, Budd-Chiari is associated more generally with hypercoagulable states, polycythemia vera, postpartum states, and HCC.

Hepatic cirrhosis can be ruled out based on the time course of the patient's presentation - he was fine 2 weeks ago and the abdominal pain started an hour ago.