Liver-Occupying Focal Nodular Hyperplasia and Adenomatosis Associated with Intrahepatic Portal Vein Agenesis Requiring Orthotopic Liver Transplantation

Abstract

An 11-year-old Hispanic girl presented to our hospital with persistent abdominal pain. She was known to have a focal nodular hyperplasia (FNH) since 3 years of age, and underwent surgical resection at 4 years old due to severe abdominal pain. She remained asymptomatic until recently, but recurrence was noted at the age of 7 years. Over the past several weeks, she has been experiencing moderate to severe episodes of right upper quadrant pain which was only partially ameliorated by analgesics. The laboratory tests showed elevated alkaline phosphatase 737 U/L, ALT 125 U/L and ALT 70 U/L, but were otherwise normal including alpha-feto-protein. Metabolic disorders and autoimmune liver disease were ruled out, and serologies including hepatitis A, B, and C viruses and cytomegalovirus were negative. An abdominal computed tomography (CT) scan revealed numerous lesions, up to 6.5 cm in diameter, filling the liver (Fig. 1A). Three-dimension CT showed blood flow from the confluence of the superior mesenteric vein (SMV) and splenic vein (SV) directly draining into the inferior vena cava (IVC), and no portal venous flow into the liver (Fig. 1B).FIGURE 1.: (A, B) Computed tomography (CT) scan of the abdomen. (A) An axial tomography scan showed multiple varying-sized lesions filling the liver, with the size of up to 6.5 cm in diameter. (B) Three-dimensional restructuring image of CT revealed a blood flow shunt of the superior mesenteric vein and splenic vein draining into the inferior vena cava directly outside the liver without any flow of portal vein into the liver. A, abdominal aorta; I, inferior vena cava; P, portal vein; Sp, splenic vein; S, superior mesenteric vein. (C) Macroscopic examination of the specimen. Multiple varying-sized well-circumscribed tan-golden nodules, which had thin, fibrous septae traversing throughout, were occupying the liver. (D) Histological examination of the specimen (H&E stain, ×40). All the nodules exhibited scarring, and there were also abundant solitary arteries within the surrounding nodular tissues.Although other options including ablation therapy were considered, surgical intervention was chosen due to progressive, recurrent, and liver-occupying characteristics of the tumors. She was approved for liver transplantation and underwent orthotopic liver transplantation. During the operation, the direct portocaval connection underneath the pancreas, and the absence of portal vein (PV) into the liver were confirmed. Liver transplantation was done in a piggyback fashion, and portoportal flow was established after the recipient PV detached from the IVC. Pathologic examination of the specimen showed multiple varying-sized well-circumscribed tan-golden nodules ranging from 1.3 to 5.8 cm, having a rubbery consistency with thin, fibrous septae traversing throughout (Fig. 1C). All the nodules exhibited scarring, but there were also abundant solitary arteries within the surrounding nodular tissues (Fig. 1D). There were no atypical cells in the nodules, nor cirrhosis in the background liver tissue. The diagnosis of both multiple FNH and adenomatosis was made. She recovered well and was discharged on postoperative day 10. Intrahepatic portal vein agenesis (IPVA), or congenital absence of portal vein, represents a portosystemic shunt in which there is no portal perfusion of the liver (1, 2). Embryologically, the portal vein derives from selective involution and persistence of the vitelline venous system. Abnormal involution and persistence may result in an absence of a PV (1). IPVA is a rare congenital anomaly and only 28 cases have been reported in the literature to our knowledge (1–4). Benign hepatic neoplasms including focal nodular hyperplasia (FNH) and adenoma are frequently associated with IPVA (5). Abnormalities of hepatic circulation have been suggested as possible etiological factors in benign nodular hepatocellular lesions (5). Both the arterial and portal blood flows may be impaired by anomaly or variation of the portal tract, and this blood flow disturbance is thought to cause hyperplasia and consequent nodule formation in areas with a richer blood flow (5). Hepatic resection was required in some reported cases due to progressive growth of those hepatic nodules (3, 4). One patient with IPVA and hepatoblastoma was treated by liver transplantation. The current report is the first case of IPVA associated with progressive benign hepatic nodules successfully treated by liver transplantation. Although hepatic nodules including FNHs and adenomas are histologically benign, the persistent severe abdominal pain associated with these liver-occupying lesions, as well as their progressive growth characteristics, lead us to surgical intervention. Our case extends the indications for liver transplantation to treatment of IPVA with progressive hepatic nodules. Shiro Fujita Kristin L. Mekeel Takahisa Fujikawa Robin D. Kim David P. Foley Alan W. Hemming Richard J. Howard Alan I. Reed Division of Transplantation and Hepatobiliary Surgery, Department of Surgery, University of Florida College of Medicine, Gainesville, FL Lisa R. Dixon Department of Pathology, University of Florida College of Medicine, Gainesville, FL