Abernethy malformation: congenital absence of the portal vein.

1Department of Internal Medicine; 2Department of Gastroenterology and Hepatology, Western University, London, Ontario; 3Department of Gastroenterology, King Khalid University Hospital, King Saud University, Saudi Arabia Correspondence: Dr Lukasz Kwapisz, Department of Internal Medicine, Western University, 147 Ocean Pearl Street, Whitby, Ontario L1N 0C7. Telephone 226-919-4034, e-mail lukaszkwapisz84@hotmail.com Received for publication June 29, 2014. Accepted September 17, 2014 CASE PRESENTATION A 20-year-old previously well man presented with unintentional 6.75 kg (15 lb) weight loss over a six-month period, vague abdominal discomfort and bilateral patchy rash. Blood work was notable for elevations in alanine aminotransferase (75 U/L [normal range <41 U/L]), aspartate aminotransferase (101 U/L [<40 U/L]), alkaline phosphatase (310 U/L [40 U/L to 129 U/L]) and total bilirubin (15.7 μmol/L [3.4 μmol/L to 17 μmol/L]) levels. An abdominal ultrasound revealed hepatic nodules. On further characterization, magnetic resonance imaging revealed a portosystemic shunt (PSS) between the main portal vein and inferior vena cava (IVC) (Figure 1). Both vessels were dilated, with no definite intrahepatic portal venous branches identified (Figure 2). Multiple large regenerative nodules could also be identified. Hepatic portal venous Doppler confirmed an extrahepatic PSS, with a markedly distended infrahepatic IVC (Figure 3). The confluence of the splenic vein and superior mesenteric vein drained directly into the IVC. The morphology suggested a type Ib Abernethy malformation.