Bile Duct Adenomas are small (<1cm), well-circumscribed, often subcapsular lesions, and historically considered benign lesions.   - Definition = composed of non-cystic (i.e., not fluid filled) biliary structures within a dense fibrous stroma.  - Imaging characteristics = Typically presents as a small, well-circumscribed subcapsular solid lesion, often incidentally detected. On CT or MRI, lesions show arterial phase enhancement with persistent delayed enhancement due to dense fibrous stroma. MRI usually demonstrates T1 hypointensity and mild to moderate T2 hyperintensity. Lack of washout and small size favor benignity, though imaging may overlap with metastases.  Special considerations =   - Historically thought of as very indolent.   - More recent concern that there could be a link with malignant transformation to cholangiocarcinoma in select bile duct adenomas with BRAFV600E mutations.   Treatment & Surveillance   - The vast majority can be considered an incidental finding.   - If imaging or clinical concerns are present, consider excisional biopsy.