[1559] Value of Immunohistochemistry of Hepatocellular Adenomas: A Series of 79 Cases

C Bazille, M Karanian- Philippe, B Alkofer, N Le Stang, L Chiche, P Rousselot, F Galateau-Salle. CHU Caen, Caen, France

Background: A large series of hepatocellular adenomas (HA) was reviewed to compare their morphological and immunohistochemical (IHC) phenotypes and evaluate the usefulness of IHC.
Design: 79 resected HA, including 25 adenomatosis, collected from 1992 to 2009 were classified according to morphology and immunohistochemistry – Liver Fatty Acid Binding Protein (LFABP), SAA, Glutamin Synthetase (GS) and β-catenin (BC) antibodies. Results were validated by molecular biology in some frozen samples.
Results: Median age was 39 years (range 14-66) with a M/F ratio of 1/8. 72% of women received oral contraception with mean duration of 19 years. Morphologically there were 21 steatotic (26.6%), 35 inflammatory (44,3%), 2 atypical (2,5%) and 21 unclassified (26,6%) HA. IIHC analysis of 79 cases gave 4 subtypes: HNF1a-mutated HA (LFABP neg), n=25 (31,6%); BC-activated HA (SAA -ve, GS high, BC +ve, n=1 (1,3%); inflammatory HA (SAA +ve), n=39 (49,4%) including 3 inflammatory with BC-activated HA (SAA+ve, GS high, BC +ve); and non-specific immunophenotype HA (LFABP +ve, SAA -ve, GS low), n=14 (17,7%). 20/25 (80%) of HNF1α-mutated HA and 30/39 (77%) of inflammatory HA are correctly classified according to morphology only. 7/21 (33%) of non-specific HA and 18/79 (22,8%) of HA were reclassified after IHC, notably IHC detected 2/4 of BC-activated HA without significant atypia. Men comprised 82% of inflammatory HA. Two patients developed hepatocellular carcinoma (1 inflammatory and 1 unclassified). Adenomatosis cases were divided up by 15 HNF1α-mutated, 7 inflammatory and 3 unclassified HA.
Conclusions: Clinico-pathological results of our series correlated with the literature. IHC analysis is helpful for HA subtyping in case of non-specific features and particularly for BC-activated HA with a high risk of malignant transformation.
Category: Liver & Pancreas

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 222, Tuesday Morning


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