[Hepatic angiomyolipoma simulating hepatocytic tumor. 3 cases]

Hepatic angiomyolipoma is a rare, benign, mesenchymal tumor. We report 3 cases of atypical angiomyolipomas simulating benign hepatic tumors in 3 women free of tuberous sclerosis (Bourneville's disease). Hepatic angiomyolipomas were solitary in 2 cases and multiple in one. At imaging, the 6 lesions were large (7 cm in mean diameter), mainly hypoechoic and heterogeneous. At CT, lesions did not contain fat and were hypervascular. At MR imaging, lesions were hypointense in 4 cases and isointense in one case on T1-weighted sequences, hyperintense and isointense on T2-weighted sequences in four and in one case respectively. Percutaneous biopsy, performed in 2 cases, did not provide a correct diagnosis. Histopathologic examination of the resected specimen showed angiomyolipomas with very low or lacking fat in all 3 patients. All lesions were positive with the HMB-45 antibody. In conclusion, hepatic angiomyolipoma with a low fat component may mimic other hepatic tumors. Diagnosis may be improved by using HMB-45 reactivity on the biopsy specimen.