Giant hepatic angiomyolipoma simulating focal nodular hyperplasia

A case of hepatic angiomyolipoma occurring in a 41-year-old woman, the eighteenth case in literature, is reported herein. The radiographic imagings of the tumor simulated those of focal nodular hyperplasia; namely, the tumor was hyperechoic on ultrasound, hypodense on computed tomography, hypervascular on angiography, and exhibited an uptake of technetium (Tc)-99m phytate. The diagnosis was established after successful removal of the huge tumor from the right hepatic lobe. Histologically, the tumor was angiomyolipoma which was made up of three components, blood vessels, smooth muscle and fatty tissue. Furthermore, extramedullary hematopoiesis, which is usually seen in this tumor was confirmed. The differentiation of hepatic angiomyolipoma from FNH is also discussed.