Biliary adenofibroma in a setting of primary biliary cholangitis and small duct destruction

Biliary adenofibroma (BAF) is a very rare benign fibroepithelial neoplasm of the liver with the potential for malignant transformation. Most published cases present with either nonspecific clinical symptoms or are asymptomatic, typically with unremarkable laboratory findings. To the best of our knowledge, this is the first reported case of BAF in the setting of Primary Biliary Cholangitis (PBC). We present a finding of BAF in a 56-year-old woman with end-stage liver disease due to PBC. The explant liver showed a 2 cm area of distinct yellow-green nodularity in segments 7–8, with microscopic features diagnostic of BAF. We provide a comprehensive literature review of BAF, including characteristic histopathological findings of both benign and malignant forms, a review of pathogenesis, and a brief description of molecular and/or genetic alterations. These findings expand the clinicopathologic spectrum of BAF and underscore its occurrence in the setting of chronic cholestatic liver disease, with implications for recognition and assessment of malignant potential.