Hepatocellular carcinoma in an adult patient with congenital absence of the portal vein type II: A case report.

Congenital absence of the portal vein (CAPV) is a rare malformation in which intestinal and splenic venous blood bypasses the liver and drains into systemic veins. CAPV is classified into two types based on the absence (type I) or presence (type II) of portal venous flow into the hepatic parenchyma and is associated with multiple other anomalies such as usually benign hepatic tumors. There have been only two case reports describing hepatocellular carcinoma (HCC) in patients with CAPV type II to date. We report the third such patient. A 50-year-old woman was referred to our hospital for management of a giant hepatic tumor. Contrast-enhanced computed tomography (CECT) indicated a huge mass occupying the right lobe of the liver; the radiological diagnosis was HCC. CECT also demonstrated that the superior mesenteric vein (SMV) and the splenic vein (SpV) joined to form a shunt draining into the left renal vein and that a hypoplastic portal vein branched from the confluence of the SMV and SpV and drained into the liver, indicating that the CAPV was type II. Liver resection was successfully performed to treat the HCC, and the pathological diagnosis was well-differentiated HCC. Seven months after the operation, a recurrent small HCC was detected and treated with radiofrequency ablation without complications. The patient has been carefully followed for 6 months to date without any evidence of further recurrence. Patients with CAPV are predisposed to developing HCC and require close surveillance.