%0 Journal Article %T Hepatocellular Adenoma: Evaluation with Contrast-Enhanced Ultrasound and MRI and Correlation with Pathologic and Phenotypic Classification in 26 Lesions %A Anne-Fr¨¦d¨¦rique Manichon %A Brigitte Bancel %A Marion Durieux-Millon %A Christian Ducerf %A Jean-Yves Mabrut %A Marie-Annick Lepogam %A Agn¨¨s Rode %J HPB Surgery %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/418745 %X Purpose. To review the contrast-enhanced ultrasonographic (CEUS) and magnetic resonance (MR) imaging findings in 25 patients with 26 hepatocellular adenomas (HCAs) and to compare imaging features with histopathologic results from resected specimen considering the new immunophenotypical classification. Material and Methods. Two abdominal radiologists reviewed retrospectively CEUS cineloops and MR images in 26 HCA. All pathological specimens were reviewed and classified into four subgroups (steatotic or HNF 1¦Á mutated, inflammatory, atypical or ¦Â-catenin mutated, and unspecified). Inflammatory infiltrates were scored, steatosis, and telangiectasia semiquantitatively evaluated. Results. CEUS and MRI features are well correlated: among the 16 inflammatory HCA, 7/16 presented typical imaging features: hypersignal T2, strong arterial enhancement with a centripetal filling, persistent on delayed phase. 6 HCA were classified as steatotic with typical imaging features: a drop out signal, slight arterial enhancement, vanishing on late phase. Four HCA were classified as atypical with an HCC developed in one. Five lesions displayed important steatosis (>50%) without belonging to the HNF1¦Á group. Conclusion. In half cases, inflammatory HCA have specific imaging features well correlated with the amount of telangiectasia and inflammatory infiltrates. An HCA with important amount of steatosis noticed on chemical shift images does not always belong to the HNF1¦Á group. 1. Introduction Hepatocellular adenomas (HCAs) are uncommon primary benign tumours, usually found in young and middle-aged women, typically encountered in the presence of a long history of oral contraceptive use (OCs) [1]. HCAs can be solitary and are monoclonal tumours. They are considered now as a heterogeneous entity. Several pathomolecular features have recently been described [2, 3]. Based on two molecular criteria (HNF1¦Á mutations and -catenin mutations) and an additional histological criterion, four subgroups can be defined: HNF1¦Á mutated adenomas, ¦Â-catenin mutated adenomas, and inflammatory and/or telangiectatic adenomas; the fourth group has no particular morphological and molecular features. Each HCA subtype is potentially associated with different evolutionary risk factors. ¦Â-catenin mutated HCAs are more frequently associated with the development of hepatocellular carcinoma (HCC) whereas inflammatory/telangiectatic HCAs have a significant risk of haemorrhage and also a slight risk of degeneration [4]. The noninvasive differentiation of HCA from other benign tumours (especially with focal %U http://www.hindawi.com/journals/hpb/2012/418745/