Cirrhosis of the liver is the most common cause of portal venous congestion, congestive splenomegaly, and bleeding from esophagogastric varices. In some cases, however, portal venous congestion and its sequelae occur although the liver is not cirrhotic and even though the usual tests of hepatic function give normal findings. In the majority of cases without hepatic cirrhosis, some obstruction in the extrahepatic part of the portal venous system can be demonstrated by portal venography. The descriptive term, "extrahepatic portal obstruction," is often applied to this group of lesions in contradistinction to the term, "intrahepatic portal obstruction," which describes the results of the several types of cirrhosis of the liver. There remain a few patients with portal venous congestion who have neither cirrhosis of the liver nor demonstrable obstruction in the extrahepatic portion of the portal venous system. The cause of portal congestion in these cases is not clear. Intrahepatic portal