ANGIOMYOLIPOMA OF THE LIVER - SIGNIFICANCE OF CT AND MR DYNAMIC STUDY

Angiomyolipoma is a benign mesenchymal tumor that has been reported fr equently in the kidney but rarely in the liver. In the present study, we present four cases of hepatic angiomyolipoma with different radiolo gic appearances, discuss differential diagnosis, and review previously reported cases. One of our cases was followed for 8 years. Computed t omography (plain, enhanced, and dynamic study), magnetic resonance ima ging (T1-weighted spin echo, T2-weighted spin echo, and dynamic study) , ultrasonography, and angiography were performed in all cases. Althou gh different radiologic appearances were observed in the tumors, based on different proportions of fat, blood vessels, and muscle, three cas es were diagnosed as angiomyolipoma. In one case, it was quite difficu lt to make radiologic diagnosis; hepatocellular carcinoma with fatty m etamorphosis in part was most likely suspected, but histopathological examination revealed angiomyolipoma with few fat elements. In the pres ent study, early and prolonged enhancement of the lesion with the spec ial pattern of time density/intensity curve was significant for angiom yolipoma, and we suggest that preoperative radiologic diagnosis of the lesion is possible in most of the cases. However, it can be quite dif ficult to distinguish angiomyolipoma from some hepatocellular carcinom as with fatty metamorphosis.