Hypoplasia of the right hepatic lobe associated with portal hypertension and idiopathic retroperitoneal fibrosis.

A 22-year-old man was referred to our hospital because of thrombocytopenia. Abdominal computed tomography (CT) revealed hypoplasia of the right hepatic lobe, the development of porto-systemic collateral vessels, splenomegaly and a periaortic soft-tissue mass. Laboratory tests and needle liver biopsy indicated no evidence of liver cirrhosis. Consequently, a diagnosis of hypoplasia of the right hepatic lobe associated with portal hypertension and idiopathic retroperitoneal fibrosis was established. Portal hypertension and hypersplenism was thought to be the cause of the thrombocytopenia. CT arterioportography revealed that anomalies of the portal venous system could have resulted in the hypoplasia of the right hepatic lobe. This is the first report describing hypoplasia of the right hepatic lobe accompanied by supervening idiopathic retroperitoneal fibrosis.