Correlation of MRI and CT findings with histopathology in hepatic angiomyolipoma

Hepatic angiomyolipomas are rare and often mimic other liver tumors. The ai m of our study was to describe the CT and MRI findings and to correlate ima ging features with histopathology. The CT and/or MR images were available f or retrospective analysis in seven patients. Patients had non-enhanced as w ell as enhanced CT (n = 6) or MRI (n = 4) before and after administration o f Gd-DTPA (n = 2) or MnDPDP, a liver specific contrast agent, (n = 3). In t hree patients CT and MRI did not detect fat, and in two patients the angiom yolipomas were also histopathologically devoid of fat. Vascularity ranged f rom hypervascular (n = 4) with arteriovenous shunts (n = 1) to equal (n = 1 ) or less (n = 2) postcontrast enhancement compared with the normal liver p arenchyma. No uptake of the liver specific contrast agent, MnDPDP, was obse rved (n = 3). Predominantly, CT and MRI did not include angiomyolipoma in t he differential diagnosis, and the initial histopathological evaluation was inconclusive in more than half the cases. Hepatic angiomyolipomas frequent ly manifest as solitary well-circumscribed heterogeneous masses in patients with no underlying liver disease or elevation of serum tumor markers. If p resent, the demonstration of intratumoral fat is helpful in the diagnosis o f angiomyolipoma. The final diagnosis can be obtained by immunohistochemist ry.