Case 177: Congenital Absence of the Portal Vein with Hepatic Adenomatosis
Radiology: Volume 262: Number 1 -January 2012
Mohamed K. Asran, MD2 Evelyne M. Loyer, MD Harmeet Kaur, MD Haesun Choi, MD
History: A 61-year-old woman who had recently undergone resection of a left hepatic lobe mass visited our institution for a second opinion. Prior to hepatic resection, she had presented to a local emergency room with sudden-onset severe right-sided abdominal pain. Computed tomography (CT) performed at that time for suspicion of a renal stone revealed hepatic masses.
She had a history of papillary thyroid carcinoma that had been treated with radioactive iodine. The findings of a physical examination performed at the time of presentation to our institution were unremarkable. Laboratory study results were essentially normal except for a mildly elevated serum alkaline phosphatase level (161 IU/L; normal level, 38-126 IU/L). Serum a-fetoprotein level was 1.3 ng/mL (1.3 μg/L) (normal level, >5.0 ng/mL [>5.0 μg/L]). Magnetic resonance (MR) imaging and CT of the abdomen were performed.
Imaging Findings: Contrast material-enhanced CT revealed that the portal vein was absent and that the superior mesenteric vein joined by the splenic vein drained directly into the inferior vena cava. Consequently, the hepatic artery was the primary blood supply to the liver. The liver was within normal limits for size and configuration, but multiple hypoattenuating lesions, only a few of which are shown here, were noted scattered throughout both lobes (Fig 1). On MR images, almost all of the lesions were nearly isointense to the liver on unenhanced in-phase gradient-echo Tl-weighted images (Fig 2a, 2b) and on T2-weighted images (Fig 3a). On out-of-phase gradient-echo Tl-weighted images (Fig 2c, 2d), there was a substantial homogeneous signal intensity decrease in all the lesions, suggesting the presence of intralesional fat. MR imaging performed with a hepatobiliary specific contrast agent, gadoxetate disodium (Eovist; Rayer Healthcare Pharmaceuticals, Wayne, NJ), demonstrated that the hepatic masses showed only mild enhancement during the arterial phase on Tl-weighted images (Fig 3c); the lesions remained hypointense relative to the liver on 5- (not shown) and 20-minute postcon-trast Tl-weighted images with little gadoxetate disodium enhancement (Fig 3d).