Difficulty in differentiating hepatic angiomyolipoma from hepatocellular carcinoma: A case report

Differentiating hepatic angiomyolipoma and hepatocellular carcinoma(HCC) is a critical issue in setting of which hepatocellular carcinoma is epidemic. A routine physical examination revealed a hepatic tumor in an asymptomatic 44-year old woman. Computer tomography(CT) revealed a 9 x 6.5 x 7 cm well-circumscribed heterogenous soft tissue mass which showed good contrast enhancement. Several low-density foci occupying inferior aspect of lateral segment of liver were also demonstrated. Angiography showed the tumor stain with coarse vessels at peripheral region without arterioportal shunt. In- and out-phase fast multiplanar spoiled GRASS sequence magnetic resonance imaging (MRI) confirmed fatty component of the corresponding low-density area. Pathology revealed mixed typed angiomyolipoma by characteristic HMB-45 immunomarker stain. While combining CT and MRI clearly demonstrates the presence of fat, the pattern of fat distribution does not allow satisfactory differentiation between angiomyolipoma and hepatocellular carcinoma. Conclusive diagnosis was also not possible to be made by the use of angiography only.