Hepatic angiomyolipoma: a case report

We experienced a rare case of hepatic angiomyolipoma (AML). A 66-year old Japanese female presented inhomogeneous echogenic lesion in the lateral segment of the liver on ultrasonography. Contrast computed tomography (CT) revealed early arterial enhancement within the lesion that stayed hyperdense in the equilibrium phase. Magnetic resonance imaging (MRI) demonstrated a non-homogeneous and partially high intensity mass on both T1- and T2-weighted images. Selective hepatic digital subtraction angiography (DSA) showed the lesion to be inhomogeneously hypervascular, supplied via branches of the left hepatic artery. The patient underwent elective left hemihepatectomy. Microscopic findings demonstrated that the tumor was composed of fat cells, blood vessels, and smooth muscle cells. Most of the spindle cells were immunoreactive to homatropine methylbromide 45 (HMB-45), alpha-smooth muscle actin and Melan-A/MART-1. Morphological pattern and immunophenotype were consistent with hepatic angiomyolipoma.