Hepatocellular adenoma (HCA) is a rare, benign liver tumor. Discovery of this tumor is usually as an incidental finding, correlated with the use of oral contraceptives, or pregnancy. Treatment options have focused on conservative management for the straightforward, smaller lesions (<5 cm), with resection preferred for larger lesions (>5 cm) that pose a greater risk of hemorrhage or malignant progression. In recent years, a new molecular subclassification of HCA has been proposed, associated with characteristic morphological features and loss or increased expression of immunohistochemical markers. This subclassification could possibly provide considerable benefits in terms of patient stratification, and the selection of treatment options. In this review we discuss the decision-making processes and associated risk analyses that should be made based on lesion size, and subtype. The usefulness of this subclassification system in terms of the procedures instigated as part of the diagnostic work-up of a suspected HCA will be outlined, and suitable treatment schemes proposed.ypically, HCAs are treated conservatively, with patients advised to avoid oral contraception. The risks of growth and rupture of HCAs during pregnancy has to be underlined, especially in larger HCAs. Tumor progression, suggested by internal bleeding and malignant transformation, necessitates a more aggressive therapeutic approach, with lesions larger than 5 cm considered as the primary risk factor In recent years, four distinct subtypes of HCA have been recognized: The primary differential diagnosis for HCA is focal nodular hyperplasia (FNH). If in doubt, a biopsy should be taken, especially for larger lesions, as the clinical management will differ for either pathology. In most cases these diagnoses can be differentiated according to signal intensity and dynamic vascular patterns after intravenous aspecific gadolinium injectioninflammatory HCA (40–50%, IHCA), HNF1A-mutated HCA (30–40%, H-HCA), β-catenin activated HCA (10–15% b-HCA), and unclassified HCA (10–25%, UHCA)