Applying the Bordeaux classification for genotype-phenotype reclassification of resected hepatocellular adenomas in the greater Brisbane region from 2000 to 2015

Objective: Hepatocellular adenomas (HCAs) present a diagnostic challenge due to ambiguous histological and radiological profiles, potential for malignant transformation and bleeding. The Bordeaux classification recently established that there are at least four main HCA subtypes with different genotypic characteristics. This paper applied the new classification methodology to previously resected adenomas in the Brisbane region to understand their phenotypes, clinical manifestation and malignant risk. Methods: Patients with HCA diagnosis and stored tissue were identified via the Brisbane HPB database of both public and private patients between 2000 and -2016. Pathological techniques for identifying LFABP inactivation, nuclear beta-catenin activation & Glutamine Synthatase, Serum Amyloid A & C-Reactive Protein were applied to surgically resected specimens. Operative data and clinical correlation data was obtained from patient records and follow-up surveys. Results: 118 patients (93% Female; Median Age 39 yrs), were identified with resected tissue available for reanalysis. Multiple subtypes verified the presence of a heterogeneous adenoma group; Inflammatory (47%; Type C), HNF-1 Alpha (28%; Type A) and beta-catenin (13%; Type B) and unclassifiable (13%; Type D). 18 HCAs were haemorrhagic, with 73% Type C, representing 32% of Type C lesions which was a significantly greater proportion than others (p<0.05). Seven patients had adenomatosis, but none were Type B. Conclusion: Literature suggests beta-catenin mutants predispose to malignant change (10–15% of HCAs transform) and our data verifies the presence of these mutations in HCAs, showing a heterogeneous group of tumours, however further validation required to assess HCA transformation to HCC and if a new diagnostic and management approach is warranted.