Case report: Intrahepatic portal-hepatic venous shunts associated with a huge pelvic leiomyoma

We present a case of portal-systemic encephalopathy due to intrahepatic multiple portal-hepatic venous shunts. A 71-year-old woman was admitted to our hospital because of recurrent episodes of disturbed consciousness. She showed no clinical signs of portal hypertension. Liver function was normal, except for an indocyanine green retention rate of 34% at 15 min and blood ammonia level of 282 mu g/dL. Portal venography revealed dilatation of the portal vein and multiple portal-hepatic venous shunts, and a liver biopsy specimen revealed almost normal liver. Further clinical examination revealed a huge pelvic tumour. At laparotomy, two dilated veins were seen to arise from the pelvic tumour with blood flow into the mesentery. The tumour was resected successfully and a histological diagnosis of leiomyoma was made. The blood ammonia concentration decreased to the normal range postoperatively. A follow-up portal venogram demonstrated decreased portal vein dilatation and minor portal-hepatic venous shunts, considered to be congenital in origin. It is concluded that hepatic encephalopathy was produced in this patient due to an excess portal blood flow from the huge pelvic leiomyoma via the mesentery, with portosystemic shunting through pre-existent (probably congenital) intrahepatic anastomoses.