Hepatic angiomyolipoma with early drainage veins into the hepatic and portal vein

Hepatic angiomyolipoma (AML) is a rare stromal tumor composed of variable admixtures of thick-walled vessels, smooth muscles and adipose tissue. One of the specific radiological findings of hepatic AML is an early drainage vein noted via enhanced computed tomography (CT). We report a case of hepatic AML showing early drainage veins into both the hepatic and portal vein. The case involved a 46-year-old woman who was referred to our hospital because of a giant hepatic tumor. CT revealed well-enhanced 14 cm and 1 cm tumors in the left and right lobes, respectively. Magnetic resonance imaging demonstrated the existence of adipose tissues in the larger tumor. Hepatic arteriography revealed early drainage veins draining into both the hepatic and portal vein. Based on a diagnosis of hepatic AML, left hepatectomy and partial hepatectomy were performed. Pathology revealed both tumors as hepatic AML based on human melanoma black-45 immuno-positivity. Hepatic AML with early drainage veins into both the hepatic and portal vein is rare. The dilated and retrogressive vein drains the abundant arterial blood flow of the tumor. The finding of early drainage veins into not only the hepatic vein but also the portal vein should be helpful for diagnosing hepatic AMLs.