Abstract
Abernethy malformation refer to a congenital absence of intrahepatic portal veins leading to a primarily extrahepatic congenital portosystemic shunt. The lack of intrahepatic portal veins leads to a characteristic set of physical exam and imaging findings that may include hyperandrogenism and liver masses such as hepatic adenomas or focal nodular hyperplasia. In this case report, we describe a 20-year-old female who presented with an enlarging hepatic adenoma. A separate hepatic adenoma had previously been biopsied and noted to have undergone malignant degeneration into hepatocellular carcinoma. For each lesion, she was treated with combination transarterial embolization and microwave ablation. On follow-up imaging after therapy, it was then noted that her extrahepatic portal vein drained directly into the inferior vena cava, consistent with congenital portosystemic shunt. Recognition of this vascular anomaly is critical in treatment planning, as early intervention with either medical therapy or surgery can prevent the metabolic sequela of this unique constellation of symptoms.