Hepatic angiomyolipoma: identification of an efferent vessel as a hepatic vein by contrast-enhanced harmonic sonography.

Two cases of hepatic angiomyolipoma were studied by contrast-enhanced harmonic sonography. The special tumor hemodynamics, namely the efferent blood flow of the hepatic angiomyolipoma draining into the hepatic vein, were clearly shown on harmonic imaging, and they corresponded well with those seen on angiography and computed tomography during angiography. Benign hepatic tumors were diagnosed preoperatively in both cases according to the hemodynamic findings. Hepatic angiomyolipoma was finally identified histologically. The special tumor hemodynamics might be one of the important characteristics of hepatic angiomyolipoma. Contrast-enhanced harmonic sonography is useful for the detection of special tumor hemodynamics and may facilitate the differential diagnosis from other hepatic tumors, especially malignant liver tumors.